LUBRICATING SYSTEM

Abstract

A lubrication system includes a progressive distributor that is configured to dispense lubricant to a consumer. The lubrication system also includes a control device and at least one sensor that is configured to determine at least one lubricant pressure inside the lubrication system. The control device is configured to receive measured values from the at least one sensor and to recognize a lubrication cycle based on the measured values and also to determine an average pressure of the lubrication cycle, to perform a comparison of the average pressure and at least one normal pressure of the lubrication system, and to determine a state of the lubrication system based on a result of the comparison.

Claims

1. A lubrication system comprising: a progressive distributor configured to dispense lubricant to a consumer, the progressive distributor including at least one sensor, and a control device, wherein the at least one sensor is configured to determine at least one lubricant pressure inside the lubrication system, wherein the control device is configured to receive measured values from the at least one sensor, and wherein the control device is configured to recognize a lubrication cycle based on the measured values and to determine an average pressure of the lubrication cycle, to perform a comparison of the average pressure and at least one normal pressure of the lubrication system, and to determine a state of the lubrication system based on a result of the comparison.

2. The lubrication system according to claim 1, wherein the at least one sensor is configured to measure a temperature of the lubrication system, and wherein the measured values are at least one pressure and one temperature of the lubrication system.

3. The lubrication system according to claim 1, wherein the control device is configured to detect a lubrication cycle based on pressure fluctuations of the lubrication system.

4. The lubrication system according to claim 1, wherein the control device is configured to determine a maximum pressure, a minimum pressure, and a temperature of the lubrication system.

5. The lubrication system according to claim 4, wherein the control device is configured to associate the average pressure with one of a plurality of temperature windows based on the temperature of the lubrication system.

6. The lubrication system according to claim 5, wherein the control device is configured to retrieve from a database the one of the at least one normal pressure that is associated with the one of the plurality of temperature windows.

7. The lubrication system according to claim 6, wherein the control device is configured to store the average pressure as a normal pressure for a given temperature window when no normal pressure for the given temperature window is present in the database.

8. The lubrication system according to claim 6, wherein the control device is configured to update the normal pressure for the given temperature window based on a current average pressure of the given temperature window when a fault-free operation of the lubrication system is recognized.

9. The lubrication system according to claim 1, wherein the state of the lubrication system is a fault-free operation of the lubrication system, a malfunction of the lubrication system, or no function of the lubrication system.

10. The lubrication system according to claim 9, wherein the malfunction of the lubrication system is a blockage of a lubricant line, a kink of a lubricant line, and/or a break of a lubricant line.

11. The lubrication system according to claim 1, wherein one of the at least one sensor is disposed upstream of the progressive distributor.

12. A control device for a lubrication system according to, wherein the lubrication system includes a progressive distributor configured to dispense lubricant to a consumer and includes at least one sensor configured to determine at least one lubricant pressure inside the lubrication system, and wherein the control device is configured to receive measured values from the at least one sensor, and wherein the control device is configured to recognize a lubrication cycle based on the measured values and to determine an average pressure of the lubrication cycle, to perform a comparison of the average pressure and at least one normal pressure of the lubrication system, and to determine a state of the lubrication system based on a result of the comparison.

13. A method for determining a state of a lubrication system including a progressive distributor that is configured to dispense lubricant to a consumer, the method including: determining at least one lubricant pressure inside the lubrication system by a sensor and outputting a signal indicative the at least one lubricant pressure, receiving the signal by a control device, recognizing a lubrication cycle based on the signal, determining an average pressure of the lubrication cycle, comparing the average pressure with a normal pressure of the lubrication system, and determining a state of the lubrication system based on a result of the comparing.

Description

[0039] In the following the invention is described in more detail using the exemplary embodiments depicted in the drawings. Here the exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the pending claims.

[0040] FIG. 1 shows a schematic block diagram of a general construction of a lubrication system,

[0041] FIG. 2 shows a schematic flow diagram of a method for determining a state of a lubrication system,

[0042] FIG. 3 shows a graph that represents the temporal course of a pressure level in the lubrication system of FIG. 1 including a blockage, and

[0043] FIG. 4 shows a graph that represents the temporal course of a pressure level in the lubrication system of FIG. 1 including line breaks.

[0044] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0045] FIG. 1 shows a lubrication system 1 that includes a progressive distributor 2. The progressive distributor 2 serves to dispense lubricant from a lubricant reservoir 4 via different metering pistons (not depicted in FIG. 1) to at least one consumer 6. The progressive distributor 2 serves to dispense a required amount of lubricant to the consumer 6. The progressive distributor 2 includes at least one sensor 8 that is configured to determine at least one lubricant pressure inside the lubrication system 1. The sensor 8 can be, for example, a pressure sensor. The sensor 8 can also be comprised of a plurality of sensors that can include, for example, a pressure sensor and a temperature sensor, or further sensors. Although only one sensor 8 is depicted here, which is preferably disposed at an inlet of the progressive distributor 2, it is also possible that the lubrication system 1 includes a plurality of sensors that are disposed at different points of the lubrication system 1. Depending on the number and position of the sensors, it is possible to determine further information about the lubrication system.

[0046] In order to be able to determine a state of the lubrication system 1, the lubrication system 1 includes a control device 10. The control device 10 is configured to receive measured values from the at least one sensor 8. The measured values can contain at least one pressure and one temperature of the lubrication system 1. The control device 10 is configured to detect lubrication cycles of the lubrication system 1 based on the measured values from the at least one sensor 8 and to determine the average pressure of a lubrication cycle, to compare the determined average pressure to a normal pressure of the lubrication system 1, and to determine the state of the lubrication system 1 based on the comparison result. This is explained in more detail below with reference to FIG. 2. The control device 10 can communicate with a database 12 in order to retrieve stored normal pressure values for the lubrication system 1.

[0047] The determined state can then be issued by the control device 10, for example, via an output 14. The issued state of the lubrication system 1 can be issued in the form of a visual indicator by colored output, e.g., by LEDs, as a detailed display on a screen or on a mobile device, or the like.

[0048] In the following an exemplary method is now described with reference to FIG. 2, which method is carried out by the control device 10 in order to determine a state of the lubrication system 1. In FIGS. 3 and 4, the associated signals are depicted by way of example.

[0049] In a first step S1, the measured values of the pressure sensor 8 are transmitted to the control device 10. It should be noted that in addition to the pressure sensor 8, further pressure sensors (not depicted) can be used in addition to the pressure sensor 8. Furthermore, a separate temperature sensor (not depicted) can be used in order to measure the temperature of the lubrication system 1.

[0050] The following method uses, by way of example, a pressure sensor 8 that is installed near the inlet of the progressive distributor 2 of the lubrication system 1, and monitors the pressure level in the lubricant line at this point. Due to the functioning of the progressive distributor 2, the pressure level at the inlet of the progressive distributor 2 is approximately the pressure level of a currently controlled outlet that supplies the consumer 6 with lubricant. This pressure level is dependent on the length of the downstream line, the subsequent component (further progressive distributor, lubrication point), the type of the lubrication point, the lubricant, the temperature of the lubricant, and other factors. Due to the continuous change of the controlled outlet, the pressure level changes continuously. The sequence by which the outlets of the progressive distributor 2 are controlled is always identical in a system-dependent manner. In this way a repeating pattern of the pressure level arises that is unique for each lubrication system. As can be seen in the following with reference to FIGS. 2 to 4, changes of the pattern allow conclusions about a change in the lubrication system and the type of change, for example, line break, impending blockage, etc.

[0051] The measured values of the sensor 8 are preferably present as signals that are temporally triggered. In particular, the measured values contain a pressure and a temperature of the lubrication system 1.

[0052] In step S2, the received measured values are stored as variables. For example, the variables can be stored in the form of an array wherein a plurality of values per time are present. Here the plurality of values contain at least the pressure and the temperature of the lubrication system 1 per time.

[0053] In step S3, the control device 10 then determines the start and end time points of the lubrication cycles (t.sub.z) based on the measured values. A lubrication cycle (t.sub.z) can be identified by associating pressure fluctuations that are detected in the measured values with a start and an end of a lubrication cycle.

[0054] If a lubrication cycle (t.sub.z) has been recognized, in step S4 the control device 10 establishes an average pressure per lubrication cycle (p.sub.z). Here the average pressure (p.sub.z) is in particular an average value of all pressure values of a lubrication cycle (t.sub.z).

[0055] In step S5, the control device 10 stores for the current lubrication cycle an average pressure of the lubrication cycle (p.sub.z), a maximum pressure (p.sub.max), and a minimum pressure (p.sub.min) of the lubrication cycle (t.sub.z), as well as a temperature of the lubrication cycle (t.sub.z).

[0056] In step S6, the current average pressure (p.sub.z) is subsequently associated with a temperature window (T). This occurs in a manner depending on the measured temperature of the current lubrication cycle. In order to associate the average pressure (p.sub.z) with a temperature window (T), here the control device 10 can access a database 12 wherein already existing temperature windows are stored with associated normal pressure values (p.sub.gT). If no normal pressure (p.sub.gT) is present for the current temperature window (T), the control device enters a learning phase that is explained further below.

[0057] When a normal pressure (p.sub.gT) is present for the current temperature window (T), in step S7 the control device compares the current average pressure (p.sub.z) with the temperature-dependent normal pressure (p.sub.gT) of the temperature window (T) that is stored in the database 12.

[0058] The control device 10 can subsequently classify the comparison result in step S8. Depending on how many measured values are present, the result can be coarse or fine. As a coarse classification the control device 10 can determine, for example, that the lubrication system 1 has no function (E1), that a malfunction is present (E2-E5), or that a fault-free operation is present (E6). If more precise data is available, the control device 10 can also determine a type of the malfunction (E2 to E5).

[0059] If no signal of the sensor 8 is present or no pressure changes are present in the measured values, the control device 10 determines that no function (E1) of the lubrication system 1 is present. This can be the case when there is a complete failure of the lubrication system 1 or when the sensors 8 have completely failed.

[0060] If a malfunction of the lubrication system 1 is recognized when sufficiently precise measured values are present, a subdivision into the following malfunctions can be effected:

[0061] A blockage of a lubricant line can be detected (E2) when three successive average pressure values (p.sub.z) are higher by a factor k than the temperature-dependent normal pressure (p.sub.gT), and the values continuously increase. Alternatively, a blockage can be assumed when a value of the average pressure (p.sub.z) is at least 200% above the normal pressure (p.sub.gT). A blockage is present, for example, when a lubricant line is blocked by foreign bodies or the like. In particular, this blockage can build up continuously, for example, by continuously reducing the through-flow through the lubricant line.

[0062] Such a blockage is depicted by way of example in FIG. 3, which shows a temporal course of the lubricant pressure that is measured by way of example by the pressure sensor 8. As can be seen, the pressure increases inside the region I. This indicates a blockage of the line in the lubrication system 1. In particular, it can be seen that the maximum value of the lubricant pressure increases the longer the blockage lasts.

[0063] If at least three successive average pressure values (p.sub.z) are recognized higher by a factor k than the temperature-dependent normal pressure (p.sub.gT), wherein the values increase non-continuously, this is defined as a kink in a line (E3).

[0064] If at least three successive values of the average pressure (p.sub.z) are lower by a factor k than the temperature-dependent normal pressure (p.sub.gT), with the values not dropping continuously, a line break is assumed (E4). Such a line break leads to a leakage of lubricant, whereby the pressure in the lubrication system 1 drops.

[0065] Such a line break is depicted in FIG. 4, which shows a temporal course of the lubricant pressure that can also be measured by way of example by the pressure sensor 8. Here a line break has been artificially generated in a test construction by lines being clamped off at different time points. The regions II, III and IV mark these time points that show different line breaks. As can be seen, a change can be inferred from the lubricant pressure course detected by the pressure sensor 8. With the pressure sensor 8 at the inlet of the progressive distributor 2, not only can a line break be determined at this progressive distributor 2, but also a line break at other points of the lubrication system 1. It is to be noted that each artificially generated line break has been corrected after one cycle, which is why in FIG. 4 no three successive values of the average pressure (p.sub.z) are to be seen that are smaller by a factor k than the temperature-dependent normal pressure (p.sub.gT).

[0066] If other deviations from the temperature-dependent normal pressure (p.sub.gT) are present, under certain circumstances it cannot be determined which type of fault is present, but it is recognized that a fault of the lubrication system 1 is present (E5).

[0067] If the control device 10 recognizes a regular change between the lubrication cycles and the pause times without relevant deviations of the average pressure (p.sub.z) from the temperature-dependent normal pressure (p.sub.gT), a fault-free operation is present (E6). In this case, on the one hand the control device 10 can output that a fault-free operation of the lubrication system 1 is present, and on the other hand this information can be used to update the database 12. This means that the current values are used for the learning phase SE1 to SE2 in order to be able to provide more precise information for the further operation.

[0068] The current value of the average pressure (p.sub.z) is therefore used (SE1) for the extension of the database 12 of the temperature-dependent normal pressure (p.sub.gT) of the temperature window (T). If a value is already present for the current temperature window (T), the average pressure (p.sub.z) is used to form (step SE2) a new temperature-dependent normal pressure value (p.sub.gT). This is comprised of the average of all fault-free values (p.sub.z) from a temperature window (T). In this way each time a fault-free operation (E6) is determined, the database 12 can be extended accordingly, and in this way the temperature-dependent normal pressure (p.sub.gT) becomes more precise.

[0069] If it has been recognized in step S6 that there is still no normal pressure (p.sub.gT) for the temperature window (T), in step SE1 the database 12 for the temperature window (T) is not updated, but rather extended. In this case the current measured and calculated average pressure (p.sub.z) of the temperature window (T) is stored as temperature-dependent normal pressure (p.sub.gT) for the temperature window (T). Since at the start of the operation of the lubrication system 1 it is assumed that a fault-free operation is present, this measured value can be viewed as normal pressure (p.sub.gT).

[0070] In summary, due to the above-described lubrication system and control device, and the corresponding analysis method, it is possible to determine a state of the lubrication system in a simple manner. In particular, when a malfunction is present, it can be defined more precisely based on the existing measured values.

REFERENCE NUMBER LIST

[0071] 1 Lubrication system [0072] 2 Progressive distributor [0073] 4 Reservoir [0074] 6 Consumer [0075] 10 Control device [0076] 12 Database [0077] 14 Output [0078] E1-E6 Result [0079] p.sub.z Average pressure [0080] p.sub.max Maximum pressure [0081] p.sub.min Minimum pressure [0082] S1-S8 Method steps [0083] SE1-SE2 Learning phase [0084] t.sub.z Lubrication cycle [0085] I-IV Signal regions