Patent Publication Number: US-2022228711-A1

Title: Automatic lubricator for lubricating an object

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a continuation application of and claims priority to commonly owned and co-pending U.S. application Ser. No. 16/730,180, filed on Dec. 30, 2019, the contents of which are incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an automatic lubricator and/or lubrication device for lubricating an object. The invention further relates to a lubrication system comprising such lubricator, a method of operating such lubricator, a computer program, and a non-transitory computer-readable medium storing such computer program. 
     BACKGROUND OF THE INVENTION 
     Automatic lubricators, lubrication devices, and/or lubrication systems are usually used for ensuring a smooth and reliable operation of an apparatus, engine, device, and/or industrial system by lubricating one or more objects, parts, portions, and/or members thereof. Such objects, parts, portions, and/or members can, for example, be and/or include a bearing, a shaft, or the like. 
     Generally, an automatic lubricator can automatically apply lubricant onto and/or into the object that should be lubricated during one or more lubrication actions, e.g., at a specified lubrication time, with a certain lubrication frequency and/or in certain lubrication time intervals. This can render a manual application of the lubricant unnecessary and hence allow to reduce maintenance effort and costs. Therein, a selection of an appropriate lubricant and/or time of lubrication can prevent a failure of the object, the apparatus, engine, device, and/or the industrial system, thereby allowing to extend the lifetime thereof. 
     SUMMARY OF THE INVENTION 
     According to the present disclosure, there is provided an improved lubricator that provides improved and/or enhanced functionality, e.g., in terms of reliably, quickly, efficiently, and/or accurately determining one or more lubrication parameters. 
     This is achieved by the subject matter of the independent claims, wherein further embodiments are incorporated in the dependent claims, the following description, and the appended figures. 
     According to a first aspect of the present disclosure, there is provided an automatic, automated, and/or at least partly automated lubricator for lubricating an object. Generally, the lubricator may refer to a lubrication device configured to apply lubricant onto and/or into at least a part of the object. The lubricator includes a housing with a coupling section configured to couple with a lubricant container for containing and/or containing a lubricant. The lubricant container includes a rotatable shaft with a piston to dispense the lubricant from an output and/or outlet of the lubricant container. The lubricator includes an electric motor configured to drive the rotatable shaft of the lubricant container during at least one lubrication action, such that at least a part of the lubricant is dispensable, can be dispensed, and/or is dispensed from the lubricant container during the at least one lubrication action. The lubricator includes at least one sensor arranged within the housing and configured to provide a sensor signal indicative, representative, and/or descriptive of a distance between the at least one sensor and the piston of the lubricant container. The lubricator includes a control circuitry that is configured to determine and/or monitor, based on the sensor signal of the at least one sensor and/or based on processing the sensor signal, at least one lubrication parameter indicative, descriptive, and/or representative of the at least one lubrication action. In some embodiments, the control circuitry is configured to derive the at least one lubrication parameter from the sensor signal of the at least one sensor. 
     As will be further described in the following, by means of the at least one sensor and/or the sensor signal that is indicative of the distance between the sensor and the piston, one or more lubrication parameters can be reliably, quickly, efficiently, cost-efficiently, and accurately determined. Further, by arranging the sensor in the housing of the lubricator, the lubricator can be used with different containers and/or different types of containers, which may for example differ in size, geometry, shape, volume of lubricant contained therein, or the like. Also, by arranging the sensor in the housing of the lubricator, the sensor can be used irrespective of a replacement of the container. In other words, the container can be replaced without replacing the sensor. Accordingly, the sensor may be physically and/or mechanically disconnected from the container itself, e.g., such that the sensor may be independent from the lubricant container and can be re-used even if the lubricant container has been replaced. Accordingly, costs of the sensor may not be connected and/or associated with the container or a replacement thereof. 
     Additionally, during e.g., the replacement of the lubricant container, no additional effort may be needed, such as e.g., fixing the sensor to the lubricant container. This, in turn, may reduce maintenance efforts and costs. 
     Here and in the following, the “object” can refer to any part, portion, and/or member that should be lubricated. For instance, the object can refer to a movable part of an apparatus, device, system, and/or industrial system, such as e.g., a motor, an engine, or the like. Such a movable part can, for example, be a bearing, a shaft, a drive shaft, or the like. 
     In the context of the present disclosure the at least one sensor may refer to a dedicated sensor for determining, measuring, monitoring, and/or detecting a distance between the sensor and the piston. Alternatively or additionally, the sensor may refer to a distance sensor for determining the distance between the piston and the at least one sensor. 
     It should be noted, however, that the sensor signal indicative of the distance between the sensor and the piston may be indicative of and/or correlate with a distance between the piston and any other static part of the lubricator, such as e.g., an end of the lubricator, an end of the electric motor, the housing of the lubricator, an immovable control part of the lubricator, the control circuitry of the lubricator, and/or any other static part of the lubricator. 
     The at least one sensor is arranged in and/or within the housing. This may mean that the sensor is mounted and/or built inside the housing. In other words, the sensor may be at least partly surrounded and/or encompassed by the housing. Alternatively or additionally, the sensor may be arranged in an interior volume of the lubricator, which interior volume may be defined by the housing of the lubricator. 
     Generally, the sensor may be arranged and/or attached to any component and/or part of the lubricator, such as e.g., a wall of the housing of the lubricator, a housing of the electric motor, an end of the electric motor, a printed circuit board of the lubricator, which may e.g., include at least a part of the control circuitry, the control circuitry, an immovable control part of the lubricator, and/or any other part and/or component of the lubricator. For instance, the sensor may be arranged adjacent and/or at an end of the electric motor, such that the at least one sensor opposes and/or faces the piston of the lubricant container, when the lubricant container is coupled to the housing. Accordingly, the at least one sensor may be arranged adjacent and/or at an end of the electric motor, which end opposes and/or faces the piston. Alternatively or additionally, the at least one sensor may be arranged adjacent and/or at a further end of the electric motor, which further end is arranged opposite to the end of the electric motor that faces the piston. Alternatively or additionally, the at least one sensor may be arranged adjacent and/or at a printed circuit board of the lubricator, which may e.g., include at least a part of the control circuitry. 
     The coupling section of the housing can be configured for being coupled to the lubricant container or at least a part thereof. For instance, the coupling section of the housing can be configured for being detachably attached and/or mechanically coupled to the lubricant container. Alternatively or additionally, the coupling section can be configured for engaging with at least a part of the lubricant container. The lubricant container and the coupling section may, for instance, be coupled via a threaded coupling or any other suitable coupling allowing to attach and/or detach the container to the housing. 
     The lubricant container (also referred to as “container”) can refer to any type of container, cartridge, can, and/or tank configured to store and/or contain a lubricant. The rotatable shaft of the container can, for example, refer to a rotatable screw. The piston of the container can be displaceably arranged on, attached to, and/or mounted to the rotatable shaft of the lubricant container. By rotation of the rotatable shaft, the piston can be moved and/or displaced along the rotatable shaft, e.g., in direction towards the output and/or outlet of the container, such that lubricant can at least partly be pushed and/or moved by the piston out of the output of the container to lubricate the object. 
     The electric motor can be an arbitrary type of electric motor, such as e.g., a DC motor, an AC motor, a brushed motor, or a brushless motor. The electric motor can be supplied with electrical power by a power supply of the lubricator. The power supply can be connected to a supply grid or it can include one or more batteries and/or accumulators. 
     The control circuitry may refer to a control circuit, a controller, and/or a control unit configured to actuate and/or control the electric motor. Therein, at least a part of the control circuitry may, for example, be arranged on a printed circuit board. The control circuitry may be coupled to the electric motor by one or more electric lines. The control circuitry may be configured to switch-on the electric motor. For instance, the control circuitry may switch-on the electric motor by activating the power supply for supplying electrical power to the electric motor and/or by coupling the electric motor to the power supply, e.g., based on actuating a switch arranged in a supply line connecting the power supply and the electric motor. Further, the control circuitry may be configured to switch-off the electric motor. The electric motor may be switched-off by the control circuitry e.g., by deactivating the power supply and/or by decoupling the electric motor from the power supply. 
     Further, the lubricator can include a data storage and/or data storage device. The data storage may be part of and/or may be coupled to the control circuitry. The control circuitry may include one or more processors, e.g., one or more microcontrollers or the like. The data storage may store software instructions and/or a computer program, which, when executed by the one or more processors of the control circuitry instructs the lubricator to perform the functional features and/or functionalities described above and in the following with reference to the lubricator. 
     In the context of the present disclosure the term “lubrication action” may refer to a state of the lubricator, in which the electric motor is actuated by the control circuitry, supplied with electrical power, powered, and/or driven by electrical power. Accordingly, the lubrication action may refer to and/or be indicative of a time period and/or a lubrication time period, during which the electric motor is actuated by the control circuitry, supplied with electrical power, powered, and/or driven with electrical power by the control circuitry (and/or the power supply). During the lubrication action, a certain amount of lubricant may be dispensed by the lubricator. Depending on a condition or state of the lubricant container, such as e.g., a blockage of the output, however, dispensing of lubricant may be (partly or completely) blocked, although the electric motor is actuated and/or powered. Accordingly, the term “lubrication action” can be accompanied by and/or result in dispensing a certain amount of lubricant or it can be accompanied by and/or result in powering the electric motor without dispensing lubricant, e.g., in the case of a complete blockage of the output. Both scenarios are referred to as lubrication action in the present disclosure. In other words, a lubrication action may include dispensing of lubricant and may include a lubrication attempt, during which the electric motor is actuated, but no lubricant can be dispensed, e.g., because of an output blockage, because the lubricant container is empty, because of a malfunction of the container, because of an erroneous coupling of the container to the lubricator, because no lubricant container is coupled to the lubricator, or the like. Further, the term “at least a part of the lubrication action” may refer to a partial or the entire time period of the lubrication action (and/or lubrication time period). 
     In the context of the present disclosure, the at least one lubrication parameter is indicative of, representative of, and/or descriptive of the at least one lubrication action. Therein, the at least one lubrication parameter may, generally, refer to an operational parameter or parameter descriptive, representative, and/or indicative of an operation of the lubricator and/or an operation of at least a part of the lubricator, such as e.g., the electric motor. Alternatively or additionally, the at least one lubrication parameter may be descriptive, representative, and/or indicative of a status, a state, a condition, and/or a working condition of the lubricator and/or at least a part thereof, such as e.g., an idle state, a running state, a normal working condition, and/or an abnormal working condition. Alternatively or additionally, the at least one lubrication parameter may refer to an operational parameter descriptive, representative, and/or indicative of an operation of the container and/or an operation of at least a part of the container, such as e.g., a rotation of the rotatable shaft, a movement of the rotatable shaft, a displacement of the piston, and/or a movement of the piston. Moreover, the at least one lubrication parameter may be indicative of, descriptive of, and/or representative of a state, a status, and/or a condition of the lubricant container, such as e.g., an amount of lubricant contained and/or remaining in the container. 
     Generally, the present invention may be considered as being based on the following insights and findings. It may be desirable to increase an efficiency and reliability of an object and/or a system or apparatus including the object, such as e.g., an industrial system. Preferably, an automatic lubricator should be able to detect, determine, and/or monitor one or more lubrication parameters, such as e.g., an amount of lubricant dispensed from the lubricator and/or from the container during one or more lubrication actions, a level of lubricant remaining in the container, a level of lubricant contained in the container, an error, a failure, a malfunction, and/or an abnormal work condition of the lubricator and/or the container coupled thereto. Such abnormal working condition can, for example, be a lubricant container output blockage, which may prevent proper dispensing of the lubricant from the container and could lead to insufficient lubrication of the object. Determining the one or more lubrication parameters may, for example, prevent a situation which could possibly adversely affect the object and/or the system or apparatus including the object. In turn, this could shorten a lifetime of the object and/or the system or apparatus including the object. 
     The control circuitry may be configured to determine and/or monitor, based on the sensor signal and/or based on processing the sensor signal, the distance between the sensor and the piston and/or the distance between the piston and any other part or component of the lubricator. By determining and/or monitoring the distance between the sensor (and/or any part of the lubricator) and the piston in accordance with the lubricator of the present invention, the one or more lubrication parameters can be determined and/or monitored. In particular, the one or more lubrication parameters can be determined and/or monitored in a reliable, fast, efficient, cost-efficient, and accurate manner, independent on other work conditions, such as e.g., vibration, moisture, and/or temperature. In other words, a reliable detection and/or monitoring of the lubrication parameter(s) that is independent on environmental conditions, such as e.g., vibration, moisture, and/or temperature at the site of the lubricator, can be ensured by the lubricator according to the present disclosure. Therein, the term “monitoring” of the distance and/or the at least one lubrication parameter may mean determining the distance and/or the at least one lubrication parameter over time, e.g., continuously or in certain time intervals. Further, by means of the lubricator according to the present disclosure, the cost of determining the lubrication parameter(s) as well as costs involved with replacement of the container can be minimized, since, for example, no additional time-consuming action like manual fixing of the sensor to the lubricant container may be required, e.g., when the container is replaced. Also, the invention can be used to advantage with different types of containers, independent on their, type, geometry, dimension, volume, and/or length. 
     By way of example, the control circuitry may be configured to determine, measure and/or monitor, based on the sensor signal of the at least one sensor, a displacement of the piston (e.g., during one or more lubrication actions) and/or a position of the piston, e.g., relative to a static part of the lubricator, such as e.g., an end of the lubricator, an end of the electric motor, the housing of the lubricator, a housing of the electric motor, an immovable control part of the lubricator, a drive part of the lubricator, the control circuitry of the lubricator, a printed circuit board of the lubricator, and/or any other static part of the lubricator. Based on the displacement of the piston and/or the position of the piston, the control circuitry may derive, determine, and/or monitor the one or more lubrication parameters. 
     By way of example, the displacement and/or position of the piston may be indicative of a level or amount of lubricant contained in the container. Accordingly, by determining and/or monitoring the displacement and/or position of the piston, the level of lubricant inside the container can be determined and/or monitored. While the lubricant gets dispensed, the distance between the motor and the piston may increase and a determination and/or measurement of this distance can be used to assess how much lubricant is left in the container. Optionally, based on information on the type of the container, such as, for example, a maximum displacement of the piston for said type of container, it can be determined and/or predicted when the container is empty. Also, a signal and/or warning signal can be generated upon detection and/or determination that the container is empty. 
     According to an embodiment, the at least one lubrication parameter is indicative of at least one of an abnormal working condition of the lubricator, an abnormal working condition of the lubricant container, a blockage of the output of the lubricant container, an amount of lubricant dispensed during at least a part of the at least one lubrication action, an accumulated amount of lubricant dispensed from the lubricant container in a plurality of lubrication actions, an amount of lubricant remaining in the lubricant container, a lubrication time period for the at least one lubrication action, a lubrication frequency, and a time (or time period) between consecutive lubrication actions. Accordingly, based on the sensor signal of the at least one sensor one or more lubrication parameters providing information about the lubrication action and/or the condition of the lubricator and/or the condition of the container can be determined. Therein, one lubrication parameter can be derived from another lubrication parameter. For instance, the amount of lubricant dispensed during the at least one lubrication action actually performed can be determined and added to an amount of lubricant dispensed during one or more previous lubrication actions in order to determine the accumulated amount of lubricant. This can be used to derive comprehensive information about the lubrication action, the lubricator, and/or the container based on the sensor signal and/or based on processing the sensor signal. 
     Therein, the abnormal working condition of the container and/or the lubricator may refer to a working condition, in which an actual amount of lubricant dispensed during the lubrication action differs from a pre-defined and/or target amount of lubricant, e.g., an amount that should be dispensed during the lubrication action. This can include dispensing more lubricant as well as less lubricant than the pre-defined amount of lubricant. For instance, the output and/or outlet of the container may be completely or partially blocked resulting in a reduction of the actual amount of lubricant dispensed during the lubrication action. 
     Further, the blockage of the output may refer to a partial blockage or a complete blockage of the output. The lubrication time period may refer to and/or denote the time period of the lubrication action, i.e., the time during which the electric motor is actuated by the control circuitry, is switched-on, powered, driven, and/or supplied with electric power by the control circuitry (and/or the power supply). The lubrication time period may be given as the time difference between a termination time of the lubrication action, at which the lubrication action is terminated, and a start time of the lubrication action, at which the lubrication action was started or initiated. 
     It should be noted that the present disclosure is not limited to the lubrication parameters listed above. Rather, any other lubrication parameter that is determinable based on the sensor signal can alternatively or additionally be determined. For instance, a normal working condition, such as e.g., a condition in which the actual amount of lubricant dispensed matches the pre-defined and/or target amount, and/or a start time of a subsequent lubrication action can be determined based on the sensor signal. 
     According to an embodiment, the control circuitry is configured to determine the at least one lubrication parameter based on at least one container parameter, wherein the at least one container parameter is indicative of at least one of a type of the lubricant container, a capacity of the lubricant container, a volume of the lubricant container, an initial volume of lubricant stored in the lubricant container, a geometry of the lubricant container, a shape of the lubricant container, a height of the lubricant container, and a diameter of at least a part of the lubricant container. By way of example, based on the at least one container parameter and based on the sensor signal, the amount dispensed during the lubrication action can be calculated. Further, taking into account an initial volume of lubricant in a container and the actual amount dispensed from said container during the lubrication action (or an accumulated amount of lubricant dispensed during a plurality of lubrication actions), the amount of lubricant remaining in the container after performing the lubrication action can be calculated. Also, a lifetime of the container may be determined e.g., based on the frequency of lubrication actions. 
     According to an embodiment, the at least one sensor is arranged adjacent an end of the electric motor, such that the at least one sensor opposes and/or faces the piston of the lubricant container, when the lubricant container is coupled to the housing. Arranging the sensor close to and/or at the end of the electric motor facing the piston, the distance between the sensor and the piston may be reliably determined by the control circuitry, e.g., because a region between the sensor and the piston may not be obscured or blocked by other components of the lubricator. In turn this can allow for a reliable determination of the one or more lubrication parameters. Also, by arranging the sensor at the motor&#39;s end that faces the piston, the lubricator may be provided in a compact form and may be produced in a cost-efficient manner. It should be noted, however, that the sensor can alternatively be arranged at any other, e.g., static component and/or part of the lubricator. 
     According to an embodiment, the at least one sensor is mechanically coupled to the end of the electric motor, wherein the end of the electric motor faces and/or opposes the piston of the lubricant container, when the lubricant container is coupled to the housing of the lubricator. The sensor may, for example, be arranged at, mounted to, and/or fixed at a static part of the electric motor, such as e.g., a stator and/or a housing of the motor. 
     According to an embodiment, the lubricator further includes at least one wave guide having a first end and a second end opposite to the first end, wherein the first end of the wave guide is coupled to the at least one sensor and the second end of the wave guide is directed towards the piston. Therein, the at least one sensor is configured to transmit and/or emit a measurement signal through the at least one wave guide and to receive, via the at least one wave guide, a reflected signal component of the measurement signal reflected on the piston and/or a surface thereof. Accordingly, the sensor may emit the measurement signal into the wave guide in a direction towards the piston. The measurement signal may then pass through the wave guide, wherein at least a part or component of the measurement signal may be reflected on the piston and/or a surface thereof. The reflected part or component of the measurement signal may pass through the wave guide back to the sensor, where it is received as the reflected signal component of the measurement signal. The sensor may then determine the sensor signal indicative of the distance between the sensor and the piston based on the reflected signal component and/or based on the measurement signal. By way of example, the sensor signal may be indicative of a time-of-flight of the measurement signal and the reflected signal component thereof. In this context, it should be noted that the sensor can be part of the control circuitry and the control circuitry can be configured to determine the sensor signal based on the reflected signal component and/or based on the measurement signal. Generally, the at least one wave guide may refer to any structure, e.g., a tunnel-like structure, allowing passage of at least a part of the measurement signal therethrough. The at least one wave guide may, for example, refer to a fiber optics, a channel, a measurement signal channel, or any other suitable structure. 
     According to an embodiment, the at least one sensor is at least one of a time-of-flight sensor, a laser sensor, an optical sensor, an ultrasound sensor, and a Radar sensor. These types of sensors may allow for a compact design of the lubricator, while ensuring a reliable detection and/or determination of the at least one lubrication parameter. 
     According to an embodiment, the control circuitry is configured to determine, based on the sensor signal of the at least one sensor, a first distance between the at least one sensor of the lubricator and the piston of the lubricant container before performing and/or initiating the lubrication action, and a second distance between the at least one sensor of the lubricator and the piston of the lubricant container after performing at least a part of the lubrication action or the entire lubrication action and/or upon termination of at least a part of the lubrication action or the entire the lubrication action. Therein, the control circuitry is configured to determine an amount of lubricant dispensed from the lubricant container during the at least part of the lubrication action or the entire lubrication action based on the determined first distance and the second distance. By determining the distance between the sensor before the lubrication action and after at least a part of the lubrication action or the entire lubrication action, the displacement of the piston during the at least part of lubrication or the entire the lubrication action can be determined. In turn, this may be used to compute and/or calculate the amount of lubricant dispensed during the at least part of the lubrication action or the entire lubrication, e.g., based on one or more container parameters. Further, determining the amount of lubricant dispensed during the at least part of the lubrication or the entire lubrication may be used to ensure that the object is sufficiently lubricated and/or may allow calculation of the amount of lubricant remaining in the container. 
     According to an embodiment, the control circuitry is configured to determine an amount of lubricant remaining in the lubricant container after performing the at least part of the lubrication action or the entire lubrication action based on subtracting the determined amount of lubricant dispensed during the at least part of the lubrication action or the entire lubrication action from an initial amount of lubricant stored in the lubricant container before performing the lubrication action. Determining the amount of lubricant remaining in the container may be used to determine and/or predict a time, at which the container may be empty and/or at which the container should be replaced and/or refilled. In turn, this allows ensuring proper lubrication of the object. 
     According to an embodiment, the control circuitry is configured to monitor and/or determine, based on the sensor signal of the at least one sensor, a displacement of the piston relative to the at least one sensor, wherein the control circuitry is configured to compare the determined displacement of the piston relative to the at least one sensor with at least one threshold value. Therein, the at least one threshold value may refer to a threshold value for the displacement of the piston per lubrication action and/or a threshold value for a maximum displacement of the piston. The one or more threshold values may, e.g., be stored in the data storage. Alternatively or additionally, the one or more threshold values may be retrieved from another source, e.g., via a communication circuitry of the lubricator. 
     Generally, the threshold value for the displacement per lubrication action may correspond to and/or may be indicative of a displacement of the piston during a single lubrication action and/or per lubrication action, which should result in dispensing a pre-defined and/or appropriate amount of lubricant during the lubrication. In other words, the threshold value for the displacement of the piston per lubrication action may be indicative of and/or correlate with a target amount of lubricant that should be dispensed during a single lubrication action. Accordingly, by comparing the determined and/or monitored displacement with the threshold value for the displacement of the piston per lubrication action, it may be ensured that the pre-defined and/or appropriate amount of lubricant has been dispensed during the lubrication action. 
     Further, the threshold value for the maximum displacement of the piston may be indicative of a position and/or displacement of the piston when the container is substantially empty. Accordingly, by comparing the displacement of the piston with the threshold value for the maximum displacement, the amount of lubricant remaining in the container can be determined. Alternatively or additionally, it may be determined and/or predicted when the container will be empty. Optionally, upon reaching and/or exceeding the threshold value for the maximum displacement, a signal and/or warning signal may be generated by the control circuitry. 
     According to an embodiment, the control circuitry is configured to stop the electric motor when the determined displacement of the piston relative to the at least one sensor reaches or exceeds the at least one threshold value, such that the lubrication action is terminated. Therein, the at least one threshold value may refer to a threshold value for the displacement of the piston per lubrication action and/or a threshold value for a maximum displacement of the piston. This way, it may be ensured that the pre-defined and/or appropriate amount of lubricant has been dispensed during the lubrication action. Alternatively or additionally, it may be ensured that the electric motor is not powered or driven when the container is empty and/or the threshold value for the maximum displacement has been reached and/or exceeded. 
     According to an embodiment, the control circuitry is configured to monitor and/or determine, based on the sensor signal of the at least one sensor, an amount of lubricant dispensed from the output of the lubricant container during the lubrication action, wherein the control circuitry is configured to compare the determined amount of lubricant dispensed during the lubrication action with a threshold value for the amount of lubricant, and wherein the control circuitry is configured to stop the electric motor when the determined amount of lubricant dispensed from the output of the lubricant container during the lubrication action reaches or exceeds the threshold value for the amount of lubricant, such that the lubrication action is terminated. Generally, the threshold value for the amount of lubricant may refer to a target amount of lubricant that should be dispensed during the lubrication action. Further, the threshold value for the amount of lubricant may, e.g., be stored in the data storage. Alternatively or additionally, the threshold value for the amount of lubricant may be retrieved from another source, e.g., via a communication circuitry of the lubricator. 
     According to an embodiment, the control circuitry is configured to detect a blockage of the output of the container (e.g., a partial or full blockage) by monitoring and/or determining, based on the sensor signal of the at least one sensor, the displacement of the piston over time, a distance between the sensor and the piston, and/or an amount of lubricant dispensed from the output of the lubricant container over time (e.g., a specified and/or predefined time). Therein, the control circuitry can be configured to compare an initial distance, e.g., at a first time, between the sensor and the piston with a distance measured and/or determined at a second time after the first time, and/or by comparing the amount of the lubricant dispensed over a certain time period with a threshold value. For instance, if the distance has not changed or at least not significantly over time, and/or if substantially no lubricant has been dispensed, the blockage can be detected. 
     According to an embodiment, the lubricator further includes a communication circuitry configured to transmit a signal indicative of and/or related to the determined at least one lubrication parameter. The communication circuitry may be a wired communication circuitry or a wireless communication circuitry. By way of example, the signal may be a warning signal indicating a blockage of the output of the container and/or any other lubrication parameter. Alternatively or additionally, the signal may be indicative of the amount of lubricant dispensed during the lubrication action. Alternatively or additionally, the signal may be indicative of the amount of lubricant remaining in the container after the lubrication action. Optionally, such signal may be a warning signal indicating that the remaining lubricant has reached a threshold value and/or that the container is substantially empty. This may be used to indicate to a user that the container should be replaced. 
     According to an embodiment, the control circuitry is configured to compare the at least one lubrication parameter with at least one threshold value for the lubrication parameter, wherein the control circuitry is configured to trigger transmission of the signal via the communication circuitry, when the at least one lubrication parameter reaches or exceeds the at least one threshold value for the lubrication parameter. 
     By means of the communication circuitry, an enhanced functionality of the lubricator can be provided. For instance, this provides the possibility of setting one or more parameters of the lubricator and reading one or more sets of data without the necessity of dismounting the lubricator from the lubrication site and even without coming too close to this site, as in many cases the automatic lubricators are placed in places with difficult or dangerous access. In such situation the communication circuitry, particularly providing wireless connectivity to the lubricator, can be advantageous as it can allow reducing the number of LEDS, displays, switches, and buttons mounted on the hardware, and in such a way decrease the cost while improving readability of data exchanged with the lubricator. For instance, the lubricator and/or the communication circuitry can comply with at least one wireless communication standard, such as, e.g., Bluetooth or Wi-Fi, so that it can be accessed with a user device like a smartphone or a laptop rather than with a dedicated hardware. Hence, the lubricator might be able to exchange data, signals, and/or commands with an external device which only needs to be equipped with corresponding software. Also, this can allow avoiding additional costs associated with a dedicated device designed only for communication with the lubricator. Moreover, a wireless communication can allow for placing the lubricator in hard-to-reach destinations without necessity of providing cables to connect to the device and change settings or read the data regarding the operation of the lubricator. 
     The communication circuitry may be and/or include a radio module that can be embedded into the lubricator, e.g., so that it is protected by the housing against damage, dust, and humidity. This can be of particular advantage in an environment with heavy machinery where the lubricators are normally placed. 
     Further, based on the communication circuitry, operation of the lubricator can be monitored, e.g., without necessity of visual inspection of the lubricator mounted on a machine. Based on the communication circuitry, a self-monitoring feature, which can, e.g., verify the status of the lubricator, can be implemented. For instance, a notification, a warning, a signal, a warning signal, and/or an alarm message can be transmitted via the communication circuitry and/or a corresponding communication interface that is preferably configured for wireless transmission. For instance, this can allow to recognize if the lubricator is working properly or not, without visual inspection of the lubricator. Also, a signal regarding the status of the lubricator and/or the container can be received from the lubricator, e.g., on an external device. 
     The self-monitoring feature or functionality of the lubricator, which can be implemented in the control circuitry, can recognize a situation when an immediate action should be taken and, e.g., send an alarm message. Optionally, a failure, e.g., by assessing that the level of the lubricant in the container is coming close to empty, can be predicted and a warning message can be sent before the actual failure occurs. This allows a service action to be planned in advance after the warning has been received. 
     According to an exemplary embodiment, the control circuitry is further configured to determine, estimate, compute, and/or calculate a date, time, time instant, and/or time period for a next service action for servicing the lubricator or at least a part thereof. The date, time, time instant, and/or time period can, for example, be calculated based on monitoring one or more parameters, such as, e.g., an amount of lubricant in the lubricant container, and the like. Alternatively or additionally, data and/or information related to one or more lubrication actions performed by the lubricator in the past and/or scheduled in future can be taken into account. For example, it can be determined how often or frequently lubricant is dispensed, and how much lubricant is dispensed in each. This can be used to estimate and/or determine a remaining working time until a next service action, e.g., for a change of the lubricant container, should be carried out. Further, based on such information, the date, time, time instant, and/or time period for the next service action can be determined and/or calculated. Therein, determining the date, time, time instant, and/or time period may include determining a maintenance date for servicing the lubricator. Further, the determined date, time, time instant, time period, and/or maintenance date may be transmitted via the communication circuitry, i.e., over wired or wireless communication interface, to another device which can communicate with the lubricator, such as, e.g., a gateway, a laptop, a smartphone, or any other device. 
     Generally, this can allow reducing the number of maintenance actions as the exact date and/or time of the next maintenance action can be determined. Prediction of dates when the service should be carried out may further allow minimizing the number of unnecessary maintenance actions and planning the work of the service team in advance. 
     A second aspect of the present disclosure relates the use of the lubricator and/or a lubrication system, as described above and in the following, for lubricating an object. 
     A third aspect of the present disclosure relates to a lubrication system for lubricating an object. The lubrication system includes a lubricant container configured to contain and/or containing a lubricant and including a rotatable shaft with a piston to dispense the lubricant from an output of the lubricant container. The lubrication system includes a lubricator with a housing with a coupling section coupled with the lubricant container, and an electric motor configured to drive the rotatable shaft of the lubricant container during at least one lubrication action, such that at least a part of the lubricant is dispensable from the lubricant container during the at least one lubrication action. The lubricator includes at least one sensor arranged within the housing and configured to provide a sensor signal indicative of a distance between the at least one sensor and the piston of the lubricant container. The lubricator includes a control circuitry configured to determine, based on the sensor signal of the at least one sensor, at least one lubrication parameter indicative of the at least one lubrication action. 
     A fourth aspect of the present disclosure relates to a method of operating an automatic, automated, and/or at least partly automated lubricator couplable to and/or coupled to a lubricant container. The method includes at least the steps of: actuating, with a control circuitry of the automatic lubricator, an electric motor of the lubricator to drive, during at least one lubrication action, a rotatable shaft of the lubricant container, thereby displacing a piston of the lubricant container coupled to the rotatable shaft; generating, with at least one sensor of the lubricator arranged within the housing, a sensor signal indicative of a distance between the at least one sensor and the piston of the lubricant container; and determining, with a control circuitry of the lubricator, at least one lubrication parameter indicative of the at least one lubrication action based on the sensor signal of the at least one sensor. 
     A fifth aspect of the present disclosure relates to a computer program, which, when executed by one or more processors of a lubricator and/or lubrication system, instructs the lubricator and/or lubrication system to carry out the steps of the method, as described above and in the following. 
     A sixth aspect of the present disclosure relates to a non-transitory computer-readable medium storing a computer program, which, when executed by one or more processors of a lubricator and/or lubrication system, instructs the lubricator and/or lubrication system to carry out the steps of the method, as described above and in the following. 
     It should be noted that any feature, element, step, and/or function described above and in the following with reference to one aspect of the present disclosure equally applies to any other aspect of the present disclosure. Specifically, any feature, element, step, and/or function described above and in the following with respect to the lubricator equally applies to the lubrication system and/or the method, and vice versa. 
     Further, it should be noted that any embodiment described hereinabove with reference to one aspect of the present disclosure can be combined with any other embodiment of the same or any other aspect. This may mean that any dependent claim can depend from any of the preceding claims. 
     These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following, the invention is described with reference to the appended figures which give background explanations and represent exemplary embodiments of the invention. 
         FIG. 1  shows a cross-sectional view of a lubrication system according to an exemplary embodiment, with the sensor being located beneath the electric motor. 
         FIG. 2  shows a cross-sectional view of a lubrication system according to an exemplary embodiment, with the sensor being located above the electric motor. 
         FIG. 3  shows a flowchart illustrating steps of a method of operating a lubricator according to an exemplary embodiment. 
     
    
    
     The figures are schematic only and not true to scale. In principle, identical or like parts, elements, and/or steps are provided with identical or like reference symbols in the figures. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a cross-sectional view of a lubrication system  100  according to an exemplary embodiment. 
     The lubrication system  100  includes a lubricator  10  with a housing  11  having a coupling section  12  which is coupled to a lubricant container  50  of the lubrication system  100 . The container  50  can be detachably attached to the lubricator  10  and/or the housing  11  by any suitable connection, such as, e.g., a threaded coupling and/or threaded connection. 
     The lubricant container  50  includes a rotatable shaft  52  and/or rotatable screw  52 , on which a piston  54  is displaceably arranged, mounted, and/or attached. Further, the container  50  contains a lubricant  51  which is to be dispensed via an outlet  55  and/or output  55  of the container  50 , e.g., during a lubrication action. Upon rotation of the rotatable shaft  52 , the piston  54  is displaced in a direction towards the output  55 , such that a part of the lubricant  51  is pushed out of the output  55 . 
     For driving the rotatable shaft  52  of the container  50 , the lubricator  10  includes an electric motor  16  and a control circuitry  14  for controlling and/or actuating the electric motor  16 . The control circuitry  14  can be arranged at least partly on a Printed Circuit Board  15 , PCB, arranged on a top side of the lubricator  10  opposite to the coupling section  12 , the container  50 , and/or the output  55 . The PCB  15 , however, can be arranged anywhere else. The electric motor  16  includes a rotating part (not shown) for driving the rotatable shaft and a static part (not shown). The static or immovable part may, e.g., refer to a stator and/or a motor housing of the electric motor  16 . 
     Optionally, the lubricator  10  may include a gearbox (not shown) which may be configured to change a rotational speed of the shaft  52  driven by the electric motor  16 . For instance, based on the gearbox, the shaft  52  driven by the electric motor  16  via the gearbox, can be operated at a low rotational speed with higher force when the electric motor  16  operates with higher speed and lower force, and vice versa. 
     The control circuitry  14  is further coupled to a power supply  18 , which provides the electrical power for driving the electric motor  16 , the rotatable shaft  52 , and/or the piston  54 . The power supply  18  can include one or more batteries. Alternatively or additionally, the power supply  18  may be connected to a supply grid and/or a power supply system. 
     The lubricator  10  and/or the control circuitry  14  is configured to dispense a certain amount of lubricant  51 , e.g., during a lubrication action, onto and/or into an object  102  that is to be lubricated, such as, e.g., a part, portion, and/or member of an industrial system, an apparatus, and/or device. For instance, the object  102  may be a bearing  102 . 
     Further, the lubricator  10  includes at least one sensor  30  for determining a distance  32  between the sensor  30  and the piston  54  and/or for determining a displacement  32  of the piston  54  relative to the sensor  30 . Therein, the sensor  30  is configured to provide a sensor signal indicative of the distance  32  between the sensor  30  and the piston  54  and/or the displacement  32  of the piston  54  relative to the sensor  30 . Accordingly, the sensor signal, the distance  32  and/or displacement  32  may correlate with and/or be indicative of a distance between the piston  54  and any other static part of the lubricator  10 . 
     Generally, the sensor  30  may, e.g., be a time-of-flight sensor, an optical sensor, a laser sensor, a Radar sensor, or an ultrasound sensor. 
     The sensor  30  is arranged within and/or inside the housing  11  of the lubricator  10 . In the example shown in  FIG. 1 , the sensor  30  is arranged at and/or adjacent an end  17  of the electric motor  16  and/or the lubricator  10  which end  17  faces and/or opposes the piston  54 . Accordingly, the sensor  30  may be arranged and/or located adjacent and/or at the coupling section  12 , a bottom side of the lubricator  10 , and/or a bottom side of a motor housing. 
     The control circuitry  14  is configured to process the sensor signal of the sensor  30  and to determine, based on the sensor signal, one or more lubrication parameters indicative of the lubrication action. Therein, the one or more lubrication parameters may be one or more of an abnormal working condition of the lubricator  10 , an abnormal working condition of the lubricant container  50 , a (partial or complete) blockage of the output  55  of the lubricant container  50 , an amount of lubricant  51  dispensed during at least a part of the lubrication action, an accumulated amount of lubricant  51  dispensed from the lubricant container  50  in a plurality of lubrication actions, an amount of lubricant  51  remaining in the lubricant container  50 , a lubrication time period for the lubrication action, a lubrication frequency, and a time between consecutive lubrication actions. Also, other lubrication parameters can be determined, such as, e.g., a normal working condition of the lubricator  10  and/or a start time for a subsequent lubrication action. 
     Moreover, the control circuitry  14  can compute the one or more of the lubrication parameters based on the sensor signal and based on at least one container parameter which may be descriptive of at least one of a type of the lubricant container  50 , a capacity of the lubricant container  50 , a volume of the lubricant container  50 , an initial volume of lubricant stored in the lubricant container  50 , a geometry of the lubricant container  50 , a height  31  of the lubricant container  50 , and a diameter of at least a part of the lubricant container  50 . Also, the at least one container parameter can be stored in a data storage  23  of the lubricator  10 . Alternatively or additionally, it can be retrieved and/or accessed by the control circuitry  14  via a communication circuitry  22  of the lubricator  10 . 
     Further, the control circuitry  14  may be configured to determine and/or monitor, based on the sensor signal of the sensor  30 , the displacement  32  of the piston  54  relative to the at least one sensor  30  and/or the distance  32  between the sensor  30  and the piston  54 . Therein, the determined and/or monitored displacement  32  and/or distance  32  may refer to a displacement  32  during the lubrication action or to an overall displacement  32  of the piston  54 , e.g., a displacement  32  resulting from a plurality of lubrication actions. 
     Generally, as the electrical motor  16  rotates, it rotates the rotatable shaft  52  and moves the piston  54  towards the output  55 , thereby pushing lubricant  51  out of the container  50 . Thus, when the level or amount of lubricant  51  in the container  50  is decreased, the distance  32  between the sensor  30  and the piston  54  is increased. Accordingly, by determining and/or monitoring the distance  32  between the sensor  30  and the piston  54  and/or the displacement  32  of the piston  54  relative to the sensor  30 , the one or more lubrication parameters can be reliably detected. 
     Further, the control circuitry  14  may be configured to compare the determined displacement  32  and/or distance  32  with at least one threshold value. Therein, the at least one threshold value may refer to a threshold value for the displacement  32  of the piston  54  per lubrication action and/or a threshold value for a maximum displacement  32  of the piston  54 . The one or more threshold values may, e.g., be stored in a data storage  32  of the lubricator. Alternatively or additionally, the one or more threshold values may be retrieved from another source, e.g., via a communication circuitry  22  of the lubricator  10 . 
     Optionally, a signal and/or warning signal can be triggered and/or transmitted by the control circuitry  14  via the communication circuitry  22 , when the control circuitry  14  determines that the threshold value for the displacement  32  of the piston  54  per lubrication action and/or the threshold value for a maximum displacement  32  of the piston  54  is reached and/or exceeded. For instance, a signal and/or warning signal can be triggered by the control circuitry  14  and transmitted via the communication circuitry  22  when the remaining amount of lubricant reaches a certain threshold value. Again, this can ensure proper lubrication of the object  102 , while reducing maintenance efforts and costs. 
     Generally, the threshold value for the displacement per lubrication action may correspond to and/or may be indicative of a displacement  32  of the piston  54  during a single lubrication action and/or per lubrication action, which should result in dispensing a pre-defined and/or appropriate amount of lubricant  51  during the lubrication. In other words, the threshold value for the displacement  32  of the piston  54  per lubrication action may be indicative of and/or correlate with a target amount of lubricant  51  that should be dispensed during a single lubrication action. Accordingly, by comparing the determined and/or monitored displacement  32  with the threshold value for the displacement  32  of the piston  54  per lubrication action, it may be ensured that the pre-defined and/or appropriate amount of lubricant  51  has been dispensed during the lubrication action. 
     Further, the threshold value for the maximum displacement  32  of the piston  54  may be indicative of the distance  32  and/or displacement  32  of the piston  54 , when the container  50  is substantially empty. Accordingly, by comparing the displacement  32  of the piston  54  with the threshold value for the maximum displacement  32 , the amount of lubricant  51  remaining in the container  50  can be determined. Alternatively or additionally, it may be determined and/or predicted when the container  50  will be empty. 
     Optionally, upon reaching and/or exceeding the threshold value for the maximum displacement  32 , a signal and/or warning signal may be generated by the control circuitry  14  and/or transmitted via the communication circuitry  22 . 
     Further, the control circuitry  14  may be configured to stop the electric motor  16  when the determined displacement  32  of the piston  54  relative to the sensor  30  reaches or exceeds the at least one threshold value, such that the lubrication action is terminated. Therein, the at least one threshold value may refer to a threshold value for the displacement  32  of the piston  54  per lubrication action and/or a threshold value for the maximum displacement  32  of the piston  54 . This way, it may be ensured that the pre-defined and/or appropriate amount of lubricant  51  has been dispensed during the lubrication action. Alternatively or additionally, it may be ensured that the electric motor  16  is not powered or driven when the container  50  is empty and/or the threshold value for the maximum displacement  32  has been reached and/or exceeded. 
     Moreover, the control circuitry  14  may be configured to monitor and/or determine, based on the sensor signal of the at least one sensor  30 , an amount of lubricant  51  dispensed from the output  55  of the lubricant container  50  during the lubrication action, wherein the control circuitry  14  may be configured to compare the determined amount of lubricant  51  dispensed during the lubrication action with a threshold value for the amount of lubricant  51 , and wherein the control circuitry  14  may be configured to stop the electric motor  16  when the determined amount of lubricant  51  dispensed from the output  55  of the lubricant container  50  during the lubrication action reaches or exceeds the threshold value for the amount of lubricant  51 , such that the lubrication action is terminated. Generally, the threshold value for the amount of lubricant  51  may refer to a target amount of lubricant  51  that should be dispensed during the lubrication action. Further, the threshold value for the amount of lubricant  51  may, e.g., be stored in the data storage  23 . Alternatively or additionally, the threshold value for the amount of lubricant  51  may be retrieved from another source, e.g., via a communication circuitry of the lubricator. 
     Further, the control circuitry  14  may be configured to compare the determined at least one lubrication parameter with a threshold value for the at least one lubrication parameter. Optionally, a signal and/or warning signal can be triggered and/or transmitted by the control circuitry  14  via the communication circuitry  22 , when the control circuitry  14  determines that the threshold value for the at least one lubrication parameter is reached and/or exceeded. 
     For instance, the control circuitry  14  can be configured to detect a blockage of the output  55  of the container  50  (e.g., a partial or full blockage) by monitoring and/or determining, based on the sensor signal of the at least one sensor  30 , the displacement of the piston  54  over time, a distance between the sensor  30  and the piston  54 , and/or an amount of lubricant  51  dispensed from the output  55  of the lubricant container  50  over time (e.g., a specified and/or predefined time). Therein, the control circuitry  14  can be configured to compare an initial distance, e.g., at a first time, between the sensor  30  and the piston  54  with a distance measured and/or determined at a second time after the first time, and/or by comparing the amount of the lubricant  51  dispensed over a certain time period with a threshold value. For instance, if the distance has not changed or at least not significantly over time, and/or if substantially no lubricant  51  and/or has been dispensed, the blockage can be detected. 
     The communication circuitry  22  of the lubricator  10  can be a wired communication circuitry or a wireless communication circuitry. The communication circuitry  22  can be integrated into the housing  11 . Therein, the communication circuitry  22  can include a corresponding communication interface. For instance, a signal or warning signal can be transmitted by the control circuitry  14  via the communication circuitry. 
     Due to the fact that the lubricators  10  are often placed in a location with difficult access and it is not always possible to provide wires to them, the communication circuitry  22  used for transmission of the signal, warning signal, and/or alarm message preferably is a wireless communication circuitry  22  (although not necessarily). 
     Also, any other information, data, and/or signals can be transmitted and/or received via the communication circuitry  22 . For instance, such information, data, and/or signals can relate to at least one parameter characterizing the power supply  18 , at least one parameter characterizing the lubricator  10 , and/or at least one parameter characterizing the object  102  and/or a machine on which the lubrication system  100  is mounted. 
     For example, the communication circuitry  22  can include a radio communication module, preferably enabling transmission over one or more wireless protocols, such as, e.g., Bluetooth or Wi-Fi. This allows accessing the lubricator  10  with an external device like a smartphone or a laptop, or other external devices. Also, the communication circuitry  22  can communicate, for example, with a main MCU over HCl or UART interface, or it might be an MCU with integrated radio communication. 
     The lubricator  10  further includes an indicator  20  and/or display  20  configured to display at least one information item, e.g., an information item related to the determined at least one lubrication parameter. For instance, if a blockage of the output  55  is detected and/or if the container  50  is empty, this may be indicated on indicator  20 . It should be noted, however, that any other information item can be shown or displayed on the indicator  20 , such as, e.g., an amount of lubricant  51  currently stored in the container  50 . 
       FIG. 2  shows a cross-sectional view of a lubrication system  100  according to an exemplary embodiment. If not stated otherwise, the lubrication system  100  of  FIG. 2  includes the same features, functions, and/or elements as the lubrication system  100  described with reference to  FIG. 1 . 
     In contrast to the example shown in  FIG. 1 , the lubrication system  100  of  FIG. 2  includes a wave guide  40  having a first end  42  and a second end  44  opposite to the first end  42 , wherein the first end  42  of the wave guide  40  is coupled to the sensor  30  and the second end  44  of the wave guide  40  is directed towards the piston  54 . In the example shown in  FIG. 2 , the sensor is arranged adjacent and/or at a further end  19  of the electric motor  16  opposite to the end  17  of the electric motor  16  that faces and/or opposes the piston  54 . Therein, the sensor  30  is configured to transmit a measurement signal through the wave guide  40  and to receive a reflected signal component of the measurement signal which is a part of the measurement signal that is reflected by the piston  54  and/or a surface thereof. As can be seen in  FIG. 2 , the second end  44  of the wave guide  40  is arranged at and/or adjacent the end  17  of the electric motor  16  that faces the piston  54 . By means of the wave guide  40 , the sensor  30  can be arranged at an arbitrary position within the housing  11 , while ensuring that the sensor  30  and/or the control circuitry  14  can reliably detect and/or determine the distance  32  between the sensor  30  and the piston  54 . 
     Accordingly, the sensor  30  may emit and/or transmit the measurement signal into the wave guide  40  in a direction towards the piston  54 . The measurement signal may then pass through the wave guide  40 , wherein at least a part or component of the measurement signal may be reflected by the piston  54  and/or a surface thereof. The reflected part or component of the measurement signal may pass through the wave guide  40  back to the sensor  30 , where it is received as the reflected signal component of the measurement signal. The sensor  30  may then determine the sensor signal indicative of the distance  32  between the sensor  30  and the piston  54  and/or the displacement  32  of the piston  54  relative to the sensor  30  based on the reflected signal component and/or based on the measurement signal. By way of example, the sensor signal may be indicative of a time-of-flight of the measurement signal and the reflected signal component thereof. In this context, it should be noted that the sensor  30  can be part of the control circuitry  14  and the control circuitry  14  can be configured to determine the sensor signal based on the reflected signal component and/or based on the measurement signal. 
     Generally, the at least one wave guide  40  may refer to any structure, e.g., a tunnel-like structure, allowing passage of at least a part of the measurement signal therethrough. The wave guide  40  may, for example, refer to a fiber optics, a channel, a measurement signal channel, or any other suitable structure. 
       FIG. 3  shows a flowchart illustrating steps of a method of operating a lubricator  10  and/or a lubrication system  100  according to an exemplary embodiment. The method may likewise relate to a method of lubricating an object  102 , e.g., using the lubricator  10  and/or the lubrication system  100  as described with reference to previous figures. 
     In a first step S 1 , an electric motor  16  of the lubricator  10  is actuated by the control circuitry  14  to drive, during at least one lubrication action, the rotatable shaft  52  of the lubricant container  50  and displace the piston  54  of the lubricant container  50  coupled to the rotatable shaft  52 . 
     In a further step S 2 , a sensor signal indicative of a distance  32  between the at least one sensor  30  and the piston  54  of the lubricant container  51  is generated by the at least one sensor  30  of the lubricator  10 , which is arranged within the housing  11  of the lubricator  10 . 
     In yet a further step S 3 , at least one lubrication parameter indicative of the at least one lubrication action is determined by the control circuitry  14  based on the sensor signal of the at least one sensor  30 . 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. 
     In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.