DE102017126285A1 - Measuring arrangement for lubricating oil and measuring methods - Google Patents

Abstract

Lubricants must be changed after a certain time when used in an oil circuit. The changeover time can be estimated by working hours or determined by measurement. It is proposed measuring arrangement 9 for lubricating oil 4 in an oil circuit 1 a system, with an oil chamber 10, which is part of the oil circuit 1 and flows through the operation of the plant of working oil 4a, wherein the working oil 4a in the oil circuit 1 is actively used lubricating oil 4 , with a first sensor 11a, which serves to determine a first value W1 of a parameter of the working oil 4a flowing through the oil chamber 10, wherein the measuring arrangement 9 contains a reference chamber 12 which is separable or separate from the oil circuit 1 and at least during operation of the system with reference oil 4b, wherein the reference oil 4b in the oil circuit 1 is not actively used lubricating oil 4, and the lubricating oils 4 of the reference oil 4b and the working oil 4a are originally the same, includes a second sensor 11b serving to obtain a second value W2 of the same characteristic of reference oil 4b in reference space 12,

Description

The invention relates to a measuring arrangement for lubricating oil in an oil circuit of a plant and a method for determining values of a characteristic for lubricating oil in an oil circuit of a plant.

Various installations, e.g. Vehicles or machines, each have an oil circuit for lubricating oil. The oil circuit also typically includes a filtration system, e.g. an oil filter.

From the DE 41 04 176 C2 is a monitoring device for the state of existing in machines lubricating oil known. The lubricating oil is associated with a condition sensor responsive to a transition of the lubricating oil from basic to acidic character and which is connected together with a temperature compensation means to an evaluation circuit connected to a warning device.

From the DE 100 53 250 A1 an oil-state sensor device with an ultrasonic sensor is known, from whose sensor signal oil state variables are derived. As a result, a reliable predictions of the exhaustion of the oil or the necessary time of the oil change is possible and measures to protect the engine from wear, pollution and corrosion can be initiated.

The object of the invention is to improve the measurement of lubricating oil in an oil circuit of a plant. It is another object of the invention to improve the wear detection of a system.

The object is achieved by a measuring arrangement according to claim 1 for lubricating oil in an oil circuit of a plant and by a method having the features of claim 7. Preferred or advantageous embodiments of the invention will become apparent from the other claims, the following description and the accompanying drawings.

The measuring arrangement contains an oil chamber. The oil room is part of the oil circuit. During operation of the plant, the oil space flows through working oil. The working oil is that lubricating oil that is actively used in the oil circuit. The measuring arrangement contains a first sensor. The first sensor serves to determine a first value of a parameter of that working oil which flows through the oil space.

The measuring arrangement contains a reference space. The reference space is separable from the oil circuit or actually separated from it. The reference space is at least in the operation of the system, when a measurement of the working oil to take place, filled with reference oil. The reference oil is that lubricating oil that is not actively used in the oil circuit. The lubricating oils of the reference oil and the working oil are originally the same.

The measuring arrangement contains a second sensor. The second sensor is in particular equal to the first sensor. The second sensor serves to determine a second value of the same parameter of the reference oil located in the reference space.

According to the invention, the first sensor and the second sensor are each an ultrasonic sensor. By an appropriate sensor, an ultrasonic characteristic can be determined on the lubricating oil. Corresponding parameters are particularly meaningful for the aging or wear condition of oils.

"Systems" are to be understood in the broadest sense and are in particular vehicles and machines that have lubrication through an oil circuit.

"Actively used" lubricating oil is one which is actually used in the operation of the system in the oil circuit, for example for lubrication or cooling of system components, which optionally absorbs wear particles of system components and / or the influx of foreign substances, such as water or air, subject , The reference oil is unused in this respect and therefore not exposed to such influences.

"Originally the same oil" means that at least at a certain point in time, namely "originally", working oil and reference oil are the same lubricating oils or even the same lubricating oil. For example, of a larger amount of oil of the same or the same lubricating oil part as working oil, a part used as a reference oil. The working oil is subject to the above-mentioned signs of wear or change conditions, the reference oil is not. In particular, the reference oil is at most inferior to aging and / or changes due to temperature fluctuations and / or changes due to contact with an ambient atmosphere, for example the atmosphere in an oil circuit or the ambient air.

The invention is based on the following findings or considerations:

Often, the life of an oil (lubrication period) of an oil producer in general information such as a mileage of a Vehicle or the running hours of a machine in which the oil is used. However, these values are often far from reality as oil aging is dependent on the utilization of the oil or system quality of the plant in which the oil is used. In most cases, the oil or lubricating oil before the actual lubrication period (time, when the oil is actually no longer usable), so soon, exchanged. In fact, the oil would still have the desired properties and could continue to be used.

There are currently measuring methods for the determination of the concentration and the size of particles by means of ultrasound. In such a method, the waves of different frequency are used for the determination of different particle sizes. The ultrasonic measuring principle uses transmitters with piezo element and receiver of the signal. After damping the signal, the particle size is determined. This method is problematic for use in oils, because there are other disruptive factors besides wear particles, such as air or water bubbles, which dampen the signal.

The detected ultrasonic damping of a lubricating oil by means of a suitable for the measurement task mentioned sensor is a value that characterizes the oil quality and the actual lubrication period. The use of ultrasonic sensors in an oil circuit for determining the ultrasonic damping of the lubricating oil at the location of the ultrasonic sensor is known. The idea is to compare the ultrasonic attenuation of the working oil and the reference oil.

It is assumed that when the system component is worn and / or the lubricating oil is worn, the oil property detectable by the sensor changes while the detected oil property in the reference space remains unchanged. A comparison of the detected oil properties of the first sensor and the second sensor thus makes it possible to say something about the oil properties, the age and the quality of the lubricating oil and the presence of abrasion in the lubricating oil. According to the invention, this results in the advantage that the quality, contamination and fatigue of the lubricating oil can be detected

According to the invention there is the advantage that not only a differential measurement takes place within the lubricating oil used as working oil, but a difference measurement between the working oil and the not subject to a workload reference oil can take place. Thus, different properties of the oil can be determined from its "original" properties, that is to say from its properties which it would have without any stressful or oil-changing work in a plant. The measurement on the first sensor thus corresponds to the measurement of an actual sample of the working oil or lubricating oil. The measurement on the second sensor corresponds to a reference measurement on a reference sample of the lubricating oil. Compared to a mere comparison of the measurement at the first sensor with stored reference values of the parameter, there is the advantage that the basic measurements or original properties of the lubricating oil actually used in the working oil are always newly determined as reference values by the reference measurement on the second sensor. Knowledge of exact composition, type, etc. of the lubricating oil are therefore not necessary.

In a preferred embodiment, the plant component is a motor or a tribological system. For such system components, the measuring arrangement is particularly suitable, since wear in such system components is usually detectable at the interplay of respective first and second measured values.

In a preferred embodiment, the oil circuit is part of the measuring arrangement. In other words, then an oil circuit is claimed with measuring arrangement.

In a preferred variant of this embodiment, the lubricating oil in the oil circuit is part of the measuring arrangement. In other words, then an oil circuit with lubricating oil and measuring assembly is claimed.

In a preferred embodiment, the system is part of the measuring arrangement. In other words, then a system (with oil circuit, optionally with lubricating oil) claimed with measuring arrangement.

In a preferred embodiment, each sensor, or each ultrasonic sensor, a transmitter and a receiver, wherein the transmitter and the receiver are spaced from each other by a measuring path. The measurement of the parameter supplying the sensor result takes place along this measuring path. In the case of an ultrasonic sensor, an ultrasonic pulse propagates along the measuring path. The measuring path extends at least in sections through the lubricating oil, preferably, the measuring path extends completely in the lubricating oil. In particular, the measuring section is a straight line. In particular, the transmitter comprises a piezo element for generating the ultrasound.

In a preferred variant of this embodiment, the lubricating oil is arranged as a medium, at least during the determination of a value between the transmitter and the receiver, wherein the medium, the detected ultrasonic attenuation of the Sensor influences. The lubricating oil may include degradation products and / or abrasion that affect the sensed ultrasonic attenuation. By using the lubricating oil as a damping medium in the ultrasonic sensor, it is particularly easy to determine an ultrasonic damping of the lubricating oil.

In a preferred embodiment, the parameter is therefore the ultrasonic attenuation of the lubricating oil.

In a preferred embodiment, the measuring arrangement contains an evaluation device, wherein the evaluation device is designed to compare the first value with the second value. For example, the evaluation device is designed to determine a comparison value based on the first value and the second value. Preferably, the comparison value is the difference between the second value and the first value or the amount thereof. By comparing or comparing the two values, the differences between reference oil, in particular fresh unused lubricating oil, and working oil can be defined or determined. Furthermore, the evaluation device can be designed to compare the comparison value with a tolerance value, wherein when the tolerance value is exceeded, the lubricating oil is found to be bad.

In a preferred embodiment, the reference space has an opening which can be opened, that is, can be opened, and can be closed, ie can be closed. After opening, the reference chamber is connected to the oil circuit, after closing the reference chamber is separated from the oil circuit. This offers the possibility that by opening the opening at a certain time, the oil actually present in the oil circuit can enter the reference space and thus the same oil is present in the reference space and in the oil circuit. Closing the opening keeps the oil in the reference room as a reference oil and separates it from the working oil. In the closed reference room, the reference oil is henceforth no further workload and retains - as explained above - its original properties more or less unchanged.

In a preferred variant of this embodiment, the reference space has two openings. A first opening is an inlet opening, a second opening is an outlet opening. Inlet opening and outlet opening are located in a flow path of the oil circuit. By opening both openings, the reference space is thus integrated into the oil circuit or into its flow path, so that the lubricating oil in the oil circuit also flows through the reference space. This ensures that at a desired time, the reference space is indeed completely flowed through or filled with the same oil as the rest of the oil circuit, so that when closing both openings or all openings in the reference space is actually the same lubricating oil as in the rest of the oil circuit.

In a preferred embodiment, the reference space is a partial space of the oil circuit, which is at least separable from the remaining oil circuit. The subspace is so separable or always completely separated. The separability is accomplished, for example, by the above-described oil exchange ports. In always completely separated case, for example, the reference space is filled at a certain time with the lubricating oil as a reference oil and in particular subsequently closed. The time is in particular the same time when the oil circuit is filled with the same lubricating oil as working oil.

In a preferred variant of this embodiment, the oil space is part of an interior of an oil filter housing. The oil filter housing usually contains the oil filter and is part of the oil circuit. In general, the oil filter is interchangeable with the oil filter housing. The fact that the oil space is arranged in the oil filter housing, for example, results in easy retrofitting an existing oil circuit with the measuring arrangement, because then the first sensor can be attached to the oil filter housing. The oil filter housing is usually easy and quick to replace, if a new oil filter is to be used in the oil circuit.

In a preferred embodiment, the reference space is part of an interior of an oil filter housing. The same statements apply to the reference room as have just been made for the oil room.

The object of the invention is also achieved by a method according to claim 7. The method is used to determine values of a parameter for lubricating oil in an oil circuit of a plant. In the method, a first value of the parameter is determined on a working oil, wherein the working oil in the oil circuit is actively used as a lubricating oil. A second value of the same parameter is determined on a reference oil. The reference oil is not actively used as lubricating oil in the oil circuit. However, the lubricating oils of the reference oil and the working oil are originally chosen to be the same. The first value is determined with a first sensor and the second value is determined with a second sensor, wherein the first sensor and the second sensor are designed as ultrasonic sensors. Preferably, the characteristic is an ultrasonic attenuation. The first value is in particular the ultrasonic attenuation of the first sensor surrounding the lubricating oil, wherein the second values preferably the ultrasonic attenuation of the lubricating oil surrounding the second sensor, here the reference oil.

The method and at least part of its embodiments as well as the respective advantages have been explained analogously already in connection with the measuring arrangement according to the invention.

In a preferred embodiment, a lubricating oil is first selected and then the oil circuit filled with a portion of the lubricating oil. This part of the lubricating oil is used as working oil. Another part of the same lubricating oil is used as the reference oil. This ensures that working oil and reference oil are initially selected the same.

In a preferred embodiment, the oil circuit is filled with the entire lubricating oil, i. a certain amount of lubricating oil, which is the sum of the quantities of working oil and reference oil. Subsequently, a part of the lubricating oil present in the oil circuit is used as working oil and the rest of the oil circuit existing lubricating oil from then on not actively used in the oil circuit as a lubricating oil. This oil is used as a reference oil. At the time of the separation of the reference oil from the working oil, therefore, both oils were originally selected the same. The separation makes it particularly easy to ensure that the reference space is not accidentally filled with a lubricating oil other than that of the working oil.

In a preferred embodiment, the values of the parameter are determined by respectively identical ultrasonic damping measurement on the working oil and on the reference oil. By using the same measurements, it is ensured that the values of the characteristic variable between working oil and reference oil are directly comparable and, for example, also subject to the same systematic measuring errors. By an optional difference analysis of both measured values, such systematic measurement errors can be eliminated again in favorable cases.

In a preferred embodiment, first and second values are determined simultaneously. This eliminates, for example, time effects and corresponding differences between the first and second values, since there is an instantaneous comparison between working oil and reference oil. "At the same time" means that no appreciable or measurable changes are to be expected in a possible period between the measurements, at least with regard to changes in the properties of the lubricating oil. The measurements are considered to be simultaneous if they take place within a particular period up to one second, in particular one minute or in particular one hour.

In a preferred embodiment, the method according to the invention is carried out with the aid of the measuring arrangement according to the invention.

Preferably, the quality of the lubricating oil is determined by means of a comparison of the first value and the second value. For example, by means of the comparison, the degree of contamination, the type of abrasion, the magnitude of the abrasion and / or other physical / chemical properties of the lubricating oil can be determined.

In a particularly preferred embodiment, the difference between the second value and the first value is determined or the amount of the difference. If the first value deviates from the second value by more than one tolerance value, in other words, if the difference is greater than the tolerance value, the oil is rated as bad and / or old. In particular, a measure is taken when the deviation of the first and second values is greater than the tolerance value. If the difference or deviation exceeds the tolerance level, it is assumed that the oil circuit or the system component or the oil filter is no longer in the intended condition, eg. the oil is then more contaminated by the plant component, which is an indication of increased wear in the component.

• 1 eine schematische Prinzipskizze einer Anlage mit Ölkreislauf und Messanordnung.

Further features, effects and advantages of the invention will become apparent from the following description of a preferred embodiment of the invention and the accompanying figure. Showing:

• 1 a schematic schematic diagram of a system with oil circuit and measuring arrangement.

1 shows part of an oil circuit 1 a not further shown plant, namely a part of an oil line 2 and a connected to this oil filter 3 , In the oil circuit 1 there is lubricating oil 4 passing through an oil inlet 5a from the oil line 2 in the oil filter 3 passes through and through an oil outlet 5b filtered from the oil filter 3 back to the oil line 2 arrives. The oil flow is indicated by arrows. The oil filter 3 contains an oil filter housing 8th , This contains an actual filter element 6 as well as an oil outlet space 7 of the oil filter 3 ,

1 also shows a measuring arrangement 9 for the lubricating oil 4 in the oil circuit 1 , The measuring arrangement 9 contains an oil room 10 who in 1 indicated only by dashed lines and represents no representational space, but a portion of the Ölauslassraumes 7 is. The oil room 10 is part of the oil cycle 2 That is, he is in the operation of the plant of lubricating oil 4 flows through. That in the oil circuit 1 active used lubricating oil provides working oil 4a which is the oil line 2 , the filter element 6 , the oil outlet 7 and thus also the oil room 10 flows through. A first sensor 11a serves a first value W1 a parameter, here the ultrasonic damping, of the oil space 10 flowing through working oil 4a to investigate. The measuring arrangement 9 also contains a reference space 12 , the oil cycle 1 by closing two openings 13a , b is severable. This one is with reference oil 4b filled. The reference oil 4b is in the oil circuit 1 is not actively used, but is also lubricating oil 4 and is to which the working oil 4a forming lubricating oil 4 originally the same. A second sensor 11b is equal to the sensor 11a and serves a second value W2 the same characteristic of the reference room 12 located reference oil 4b to investigate.

The reference room 12 has the openings 13a , b on, the in 1 shown pulled closed and, as indicated by dashed lines and arrows, are also openable. When closed, the reference room 12 from the oil circuit 1 separated and contains reference oil 4b , When open, the reference room is 12 with the oil circuit 1 connected. The opening 13a forms an inlet opening for the reference space 12 , the opening 13b an outlet opening. Both openings 13a , b are located in a flow path of the oil circuit 1 , which is represented by a dashed arrow. With opened openings 13a , b becomes the reference space 12 of lubricating oil 4 flows through. The entire lubricating oil 4 is then working oil 4a , The reference room 12 is a subspace of the oil circuit 1 , the rest of the oil circuit 1 by closing the openings 12a . b is separable.

In the example is the oil room 10 a part of the interior of the oil filter housing 8th , also the reference room 12 is part of the interior of the oil filter housing 8th , here in particular the Ölauslassraumes 7 , The sensor 11a . b is an ultrasonic sensor. The sensor 11a / 11b each includes a transmitter 14 and a receiver 15 , where transmitter 14 and receiver 15 are spaced by a measuring section. At least during the determination of the values W1 . W2 is the lubricating oil 4 in the form of working oil 4a or reference oil 4b between the transmitter 14 and the receiver 15 arranged. The characteristic is the ultrasonic damping of the lubricating oil 8th ,

1 also illustrates a method for determining the values W1 . W2 the parameter for the lubricating oil 4 in the oil circuit 1 , The first value W1 the characteristic is at the working oil 4a determined in the oil circuit 1 active as a lubricating oil 4 is used. The second value W2 the same parameter is the reference oil 4b determined in the oil circuit 1 not active as lubricating oil 4 is used because the openings 13a , b are closed and stay so that no mixing of the lubricating oils 4 in the reference room 12 and in the rest of the oil circuit 1 is possible. The lubricating oils 4 of the reference oil 4b and the working oil 4a are originally chosen equal.

In an alternative embodiment shown in dashed lines is the reference space 12 as well as the second sensor 11b outside the oil circuit 1 , Part of the lubricating oil 4 is sold separately as a reference oil 4b used in the reference room and there according to above with the help of the sensor 11b measured. In this embodiment, first, a lubricating oil 4 chosen and the oil circuit 1 with a part of the lubricating oil 4 filled and this as working oil 8a used. Same or the same lubricating oil 4 is used as reference oil in the reference room 12 filled.

In the embodiment shown in solid (reference space 12 in the oil filter 3 ) becomes the oil circuit 1 (with open openings 13a . b ) first with a lot of lubricating oil 4 filled. Subsequently, part of the oil circuit 1 existing lubricating oil 4 this amount as working oil 4a separated from the total and used as such. The rest in the oil circuit 1 existing lubricating oil 4 will no longer be active in the oil circuit 1 as a lubricating oil 4 but is used as a reference oil 4b used. This department is done by closing the openings 30a . b ,

The values W1 . W2 are each using the same ultrasonic attenuation measurements on the working oil 4a and the reference oil 4b determined. In the ultrasonic attenuation measurement, the lubricating oil 4 damping medium between a transmitter 14 and a receiver 15 used. The method becomes first value W1 and second value W2 determined at the same time.

The frame 16a encloses the entire oil filter 3 and indicates the measurement of the working oil 4a on. The frame 16b encloses the reference space 12 and indicates the measurement of the reference oil 4b on. The frames 16a , b enclose both alternative embodiments of the reference space 12 inside and outside the oil filter 3 ,

LIST OF REFERENCE NUMBERS

1

Oil circuit

2

oil line

3

oil filter

4

oil

5a / 5b

Oil inlet / oil outlet

6

filter element

7

Ölauslassraum

8th

Oil filter housing

9

measuring arrangement

10

oil space

11a

first sensor

11b

second sensor

12

reference room

13a / 13b

openings

14

transmitter

15

receiver

16a / 16b

frame

W1

first value

W2

second value

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 4104176 C2 [0003]
• DE 10053250 A1 [0004]

Claims (10)

Measuring arrangement (9) for lubricating oil (4) in an oil circuit (1) of a plant, - with an oil chamber (10), which is part of the oil circuit (1) and in the operation of the system of working oil (4a) flows through, said Working oil (4a) in the oil circuit (1) is actively used lubricating oil (4), - with a first sensor (11a), which serves to a first value (W1) of a characteristic of the oil space (10) flowing through the working oil (4a) Determine, characterized in that the measuring arrangement (9) - one of the oil circuit (1) separable or separate reference space (12) which is filled at least during operation of the plant with reference oil (4b), wherein the reference oil (4b) in the oil circuit ( 1) is not actively used lubricating oil (4), and the lubricating oils (4) of the reference oil (4b) and the working oil (4a) are originally the same, - a second sensor (11b) which serves to a second value (W2 ) the same characteristic of the reference oil (4) in the reference space (4 b), wherein the first sensor (11a) and the second sensor (11b) are designed as ultrasonic sensors. Measuring arrangement (9) according to Claim 1 , characterized in that the first and / or the second sensor (11a, 11b) each comprise a transmitter (14) and a receiver (15), wherein the respective transmitter (14) and the respective receiver (15) through a respective measuring path spaced apart from each other. Measuring arrangement (9) according to Claim 1 or 2 , characterized in that the first value (W1) and the second value (W2) are each an ultrasonic damping of the respective sensor (11a, 11b) surrounding lubricating oil (4). Measuring arrangement (9) according to one of the preceding claims, characterized by an evaluation device, wherein the evaluation device is designed to determine a comparison value based on the first value (W1) and the second value (W2). Measuring arrangement (9) according to one of the preceding claims, characterized in that the reference space (12) has at least one first opening (13a) as an inlet opening and at least one second opening (13b) as an outlet opening, wherein the first opening (13a) and the second opening (13b) lie in a flow path of the oil circuit (1). Measuring arrangement (9) according to one of the preceding claims, characterized in that the reference space (12) is a partial space of the oil circuit (1) and can be separated from the oil circuit (1). Method for determining values (W1,2) of a parameter for lubricating oil (4) in an oil circuit (1) of a system, in which - a first value (W1) of the parameter is determined on a working oil (4a), the working oil ( 4a) in the oil circuit (1) is actively used as lubricating oil (4), characterized in that - a second value (W2) of the same parameter is determined on a reference oil (4b), wherein the reference oil (4b) in the oil circuit (1) is not actively used as the lubricating oil (4), and the lubricating oils (4) of the reference oil (4a) and the working oil (4b) are originally chosen to be equal, wherein the first value (W1) with a first sensor (11a) is determined and the second value (W2) with a second sensor (11b) is determined, wherein the first sensor (11a) and second sensor (11b) are formed as an ultrasonic sensor. Method according to Claim 7 characterized in that - a lubricating oil (4) is selected, and - the oil circuit (1) is filled with a part of the lubricating oil (4) used as working oil (4a) and - another part of the lubricating oil (4) ) is used as the reference oil (4b). Method according to Claim 7 or 8th , characterized in that based on a comparison of the first value (W1) with the second value (W2), the quality of the lubricating oil (4) is determined. Method according to one of Claims 7 to 9 , characterized in that a measure is taken when the first value (W1) deviates from the second value (W1) more than one tolerance value.

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