Technical Field

The invention relates to a method for lubricating a machine part of a machine arrangement with a lubricant, comprising the steps of: a) determining an operation status of the machine arrangement by a control element using a signal coming from a sensor element; b) activating of a lubrication element for lubricating the machine part or intensifying the activity of the lubrication element by the control element in the case that the machine arrangement is operating and deactivating the lubrication element or decreasing its activity in the case that the machine arrangement is not operating.

Furthermore, the invention relates to a machine arrangement with a machine part, wherein a lubrication element is arranged for lubricating the machine part with a lubricant. Background

A method of the kind mentioned above is known from KR 100 741 820 Bl. Here, if was found that it is reasonable to lubricate not permanently a machine element with a lubricant but to do so only in the case that the machine arrangement is in operation. Thus, the document proposes an apparatus and a method of automatically supplying a lubricant according to detected vibrations to prevent excessive supply of the lubricant.

Single point lubricators are normally working on a time based principle. A fixed amount of lubricant (grease) is supplied during the operation. But machines which are lubricated are not always in a working operation ("on"). The machine is switched off e.g. for maintenance or in the case of holidays, etc. This means that sometimes too much lubricant is supplied.

This can be solved by turning off all lubricators manually, but this is a lot of work.

A lubicator with a vibration detector - according to mentioned KR 100 741 820 Bl - switches the lubricator automatically "on" and "off according to the machine status.

It hase been found detrimental that sometimes the judgement of the status of operation of the machine arrangement is not easy to make. Due to the demands of a quiet operation of a machine arrangement it is sometimes difficult to securely detect the machine status. Some machine arrangements create insufficient vibrations to detect with certainty whether the machine is switched "on" or "off. So, for the user it is very helpful to know if the lubricator and control element with the sensor respectively measures the state of the machine arrangement correctly. Only then it becomes possible to verify that the lubricator is "off if the machine is "off and that it is "on" if the machine is "on".

Thus, it is an o bj e c t of the present invention to further develop a method of the kind mentioned above and to propose a corresponding device which allows an easy check if the operation of the lubrication system works properly, Thus, it should become possible to better control if the detection system for the operation of the machine works correctly.

Summary of the invention

A s o l u t i o n according to the invention is characterized in that the determined operation status of the machine arrangement is signalled by the control element by an information element.

Preferably, the machine part is a bearing, especially a rolling element bearing.

The signalling can take place in a visual manner.

Also, the signalling can take place in an acoustical manner.

The operation status of the machine element can be determined by measurement of the vibration of the machine arrangement or of a part of the same by the sensor element. The operation status can be defined by the control element in dependence of the amplitude of the measured vibration signal. Also, the operation status can be defined by the control element in dependence of a frequency spectrum of the measured vibration signal.

The lubrication element can dispense a defined volume of lubricant per time in the activated mode. Also, the lubrication element can dispense periodically a defined volume of lubricant in the activated mode.

The machine arrangement has a machine part, wherein a lubrication element is arranged for lubricating the machine part with a lubricant, wherein a control element is arranged which is in connection with a sensor element for determining an operation status of the machine arrangement, wherein the control element is designed to activate the lubrication element in dependence of a determined operation status of the machine arrangement. Such a machine arrangement is characterized by the present invention in that an information element is arranged for signalling the determined operation status of the machine arrangement which information element is connected with the control element.

The information element can be a visual information element. In this case it is preferred that the information element comprises at least two light emitting elements. The light emitting elements can be light emitting diodes (LEDs). Preferably, the at least two light emitting elements emit light in different colours.

The sensor element is preferably a vibration sensor.

The device can be designed as a single point lubricator with a vibration detector. The vibration detector is measuring if the machine is "on" or "off. Depending on the state of the machine ("on" or "off) the control element adjusts the lubrication quantity and/or its timing. The lubricator and control element respectively gives a signal to show the respective status, i. e. if the detected status of the machine arrangement is "off or if it is "on". This singal can be used by the user of the machine arrangement to check if the lubricator is measuring the state of the machine correctly.

Thus, the lubricator / control element which measures if the machine is "on" or "off can be adjusted as the case may be due to the information given by the information element; so, the quantity and/or timing of the lubbrication can be optimized. In other words, the lubricator gives a signal to the operator to show if the measured state of the machine arrangement is "on" or "off so that the user can adjust the sensibility of the control element / sensor accordingly if necessary. Thus, a possible manual adjustment of the sensitivity of the measurent can be carried out by the user to improve the measurement of the state of the machine arrangement and thus the lubrication of the same.

Beneficially, it is now possible that the user of the machine arrangement can verify in an easy manner if the on/off detection of the control element is correct and thus if the lubricator works properly.

It should be noted that it is not mandatory that the lubrication element is completely switched off in the case that the machine arrangement is not operating. It can also be provided that in the later case the activity of the lubrication element is only reduced and, consequently, intensified in the case of operation of the machine arrangement. That is, it can be easy monitored if the lubrication element supplies the right quantity of lubricant in the right time, i.e. if the state of the machine arrangement is detected correctly.

It should be noted that the lubrication element can be arranged at the optimal location. This is often outside of the machine arrangement itself, i.e. the lubrication element is then a separate device and not integrated within the machine.

Brief description of the drawings

The drawing shows an embodiment of the invention.

Fig. 1 shows a schematic view of a machine arrangement and a lubrication device and

Fig. 2 shows a flow diagram of the operation of the system.

Detailed description of the invention

In Fig. 1 a machine arrangement 2 is depicted with a machine part 1. The machine part may be a roller bearing or any other machine part which requires the addition of a lubricant from time to time. To lubricate the machine part 1 a lubrication element 6 is provided which has a storage chamber for a lubricant 3. The lubricant 3 can be forwarded in a controlled manner to the machine part 1.

For doing so an electronic control element 4 is provided. The control element 4 is in connection with a sensor element 5. The sensor element 5 detects vibrations of the machine part 1 or generally of the machine arrangement 2. The control element 4 can influence the emission of lubricant 3 to the machine part 1 as indicated by the arrow which points to the connection pipe between the containing chamber for lubricant 3 and the machine part 1.

As generally known from above mentioned KR 100 741 820 Bl the emission of lubricant 3 takes not place all the time but is depends on the operation status of the machine arrangement 2. That is, if the vibration sensor 5 detects vibrations the control element 4 decides that the operation status of the machine arrangement is "on" and lubricant 3 is emitted to the machine part 1. To the contrary, if the vibration sensor 5 detects no vibrations - or vibrations below a defined threshold - the control element 4 decides that the operation status of the machine arrangement is "off and no lubricant 3 is dispensed to the machine part 1.

To allow an easy survey of the lubrication system by a user the machine arrangement comes up furthermore with an information element 7', 7" which is arranged for signalizing the determined operation status of the machine arrangement 2; the information element 7', 7" is thereby connected with the control element 4.

In the present embodiment the information element 7', 7" comprises two LEDs 7' and 7" with different colours. That is, if the detected status of the machine arrangement 2 is "on" and if thus lubricant 3 is emitted e.g. a green LED 7' is switched on by the control element 4. It the detected status of the machine arrangement 2 is "off and if thus no lubricant 3 is emitted e. g. a yellow LED 7" is switched on by the control element 4.

Thus, the information element 7', 7" gives a clear information to the user of the machine arrangement which allows a quick check if the lubrication system works properly.

This operation is also depicted in Fig. 2. Here it can be seen that at first a measurement - specifically of the vibrations of the machine arrangement 2 - takes place.

Then, an interpretation of the measures data takes place. That is, the control element 4 decides from the measured data if the operation status of the machine arrangement 2 is "on" or "off. For doing so the amplitudes of the detected vibrations and/or the frequency spectrum of the measured data can be evaluated.

According to this decision the adjustment of the lubrications quantity and/or time interval takes place. If the operation is "off the lubrication element 6 remains switched off; in the other case lubricant 3 is emitted according to the adjustment of the lubrication system.

The decision of the control element 4 if the operation mode of the machine arrangement is "on" or "off is forwarded to the operator by means of the information element 7', 7" as described. Reference Numerals:

1 Machine part

2 Machine arrangement

3 Lubricant

4 Control element

5 Sensor element

6 Lubrication element

7' Information element (LED)

7" Information element (LED)