Systems and methods for detecting the presence of particles in a lubricant flow and for analyzing particles in a lubricant flow - Patents.com

Abstract

The present invention relates to a system (10) for detecting the presence of particles in a lubricant flow and analyzing particles in the lubricant flow, the system (10) comprising a housing (1) having a channel (4) for guiding the lubricant flow and fluidly connecting a lubricant inlet (2) and a lubricant outlet (3), a particle sensor (5) configured to detect and analyze particles present in the lubricant flow, and a chip detector (6) disposed downstream of the particle sensor (5) and configured to locate and magnetically retain magnetizable particles present in the lubricant flow. The present invention also relates to a method for detecting the presence of particles in a lubricant flow and analyzing particles in a lubricant flow. The present invention also relates to a gearbox (7) comprising such a system (10).

Description

[Technical Field]

[0001] The present invention relates to a system and method for detecting the presence of particles in a lubricant flow and for analyzing particles in a lubricant flow, and further to a gearbox comprising such a system. [Background technology]

[0002] During the operation of an aircraft gearbox, metal particles, in particular ferromagnetic particles, continuously accumulate due to wear, in particular abrasion. These can accumulate in the lubricant for the gearbox. The accumulation of ferromagnetic particles, for example iron particles, can be an indicator of a fault or gradual wear in the gearbox, which can sooner or later lead to damage and ultimately failure of the gearbox. Abrasion here refers to some degree of possible early damage to gearbox components, in particular spacer components, such as cracking or wear. In particular for aircraft gearboxes, and in particular helicopter gearboxes, which must ensure safe operation over a long period of time, it is problematic that the magnetic particles cannot be easily detected from the outside.

[0003] From the prior art, magnetic plugs are known which essentially comprise a magnet and a holder for the magnet, the magnetic force of which attracts small metal particles or chips.

[0004] Detectors for chips are also known. These essentially consist of a magnet, a holder for it, and a connection that can be electrically shorted by a particle or chip in the area of ​​the magnet. Such devices are used to find and hold magnetic or magnetizable particles and to electrically indicate their presence. Detectors for chips are also known in English as "chip detectors."

[0005] U.S. Patent Publication No. 5,179,346 also discloses a device for detecting conductive particles in a fluid. The device includes a housing having first and second portions, and a magnet having first and second poles positioned within the first portion of the housing, the first and second poles defining a reference plane. A first electrode having a first contact surface is provided, positioned within the second portion of the housing and extending generally away from the magnet. A second electrode having a second contact surface is also provided, positioned within the second portion of the housing and extending generally away from the magnet. The first and second contact surfaces are spaced apart from each other and each form an angle with respect to the reference plane. The device further includes means for detecting electrical resistance between the first and second contact electrodes and for responsively generating a signal indicative of the presence of conductive particles. Summary of the Invention

[0006] The object of the present invention is to provide an efficient and safe system and method for detecting the presence of particles in a lubricant flow and for analyzing particles in a lubricant flow, and to propose a gearbox equipped with such a system.

[0007] For the purposes of the present invention, the term "analysis of particles" should be understood to mean the determination of particle size and the determination of particle accumulation over time.

[0008] This object is achieved by a system and a method for detecting the presence of particles in a lubricant flow and for analysing particles in a lubricant flow comprising the features of independent claim 1 or claim 8, and also by a gearbox comprising the features of claim 10. Preferred embodiments form the subject matter of the dependent claims.

[0009] According to a first aspect of the present invention, a system for detecting the presence of particles in a lubricant flow and analyzing particles in a lubricant flow comprises a housing having a channel for guiding the lubricant flow and fluidly connecting a lubricant inlet and a lubricant outlet, a particle sensor configured to detect and analyze particles present in the lubricant flow, and a chip detector arranged downstream of the particle sensor and configured to locate and magnetically retain magnetizable particles present in the lubricant flow. The term "system" should be understood to mean sensor devices with different measurement systems and different measurement principles for detecting and combining different measurement variables. Such a system allows for more accurate definition of measurement variable thresholds, thereby enabling more accurate wear monitoring. The present invention makes it possible to assess the progression of the amount of magnetic particles in a gearbox and, in particular, to make conclusions about the size and amount of particles present in the lubricant flow. The lubricant is guided through or through the system's channels, and it is then possible to detect whether particles are present in the lubricant flow, which particles are present, and how many particles are present, for example, as a function of time. Following this analysis by the particle sensor, at least magnetic or magnetizable particles, in particular ferromagnetic particles, are extracted from the lubricant by a chip detector and magnetically held. For this purpose, the system is preferably intended to be placed in the lubricant return line behind the gearbox parts to be lubricated and / or cooled. Such gearbox parts may be, for example, bearing elements, gears, or other gearbox parts that are exposed to mechanical loads or perform functions related to the drive, in particular the transmission of driving forces, and therefore must be lubricated and / or cooled.

[0010] The phrase "downstream of the particle sensor" should be understood to mean that the lubricant flow first passes through a particle sensor so that it can be analyzed for particles present therein, and only after that does the lubricant flow pass through a chip detector that, as it were, filters or magnetically extracts magnetic or magnetizable particles from the lubricant.

[0011] The tip detector is a magnet that closes contacts and indicates when a certain amount of magnetic particles are magnetically attracted from the lubricant flow and attached to the tip detector, the term "lubricant" being understood to mean in particular engine oil or gearbox oil.

[0012] In one embodiment, the particle sensor is designed as an oil particle sensor. In particular, the particle sensor is used to measure ferromagnetic particles in the lubricant flow. While the lubricant passes through the particle sensor, a determination is made as to whether ferromagnetic or conductive particles are present in the lubricant flow. Ferromagnetic particles are detected, for example, via a change in magnetic coupling between two coils. The particle sensor can generate an electric field, and the system can detect whether particles are present in the lubricant flow by the change in the electric field. If conductive particles are identified or detected, the system can also determine their size and the amount passing through the channel of the housing over a certain period of time. In this sense, the particle sensor is configured to analyze conductive particles present in the lubricant flow, at least in terms of size and amount. Thus, the particle sensor performs particle monitoring. The particle sensor is preferably configured so that even non-metallic particles can be detected and analyzed as long as they are at least slightly conductive.

[0013] The particle sensor interacts with particles in the lubricant flow within the channel, and the tip detector is disposed in or on the channel, with a portion of the tip detector in direct contact with the lubricant within the channel for locating and magnetically retaining magnetic or magnetizable particles in the lubricant flow.

[0014] The channels are configured so that they can be used in lubricant supplies for gearboxes or machines, for example, with a cross section that corresponds to the line cross section or channel cross section of a lubricant supply for a gearbox or machine, and preferably have a circular shape to avoid turbulence in the lubricant flow.

[0015] In the proposed system, the functions of the chip detector are integrated into a common overall system with those of the particle sensor, i.e., particle monitoring. The system can be used to assess the significance of the amount of chips in relation to their progression. At the same time, the function and efficiency of the chip detector can be guaranteed and monitored. By combining two different measurement systems and principles in a common or integral unit, the required installation space and mass are also reduced. Directing the lubricant or oil flow to the chip detector allows for safer and more accurate detection of particles as well as better collection of particles compared to prior art. The particle sensor and chip detector may be connected to a monitoring unit, which may be integrated into the gearbox and / or vehicle controller.

[0016] Preferably, the chip detector can be removably secured to the housing by interlocking and / or force-fit engagement. In other words, the chip detector is removably disposed on the housing so that it can be removed to remove deposited material. According to one exemplary embodiment, the chip detector is screwed to the housing. The chip detector may be pre-loaded to ensure a secure and positionally accurate fit on the housing.

[0017] Preferably, the particle sensor comprises a channel portion integrated into the channel, the channel portion being arranged coaxially with respect to the lubricant inlet. The channel portion forms part of the channel within the housing. The lubricant flow passes through the particle sensor, whereby the lubricant flow passing through the channel portion of the particle sensor is completely surrounded by the particle sensor to enable reliable analysis of the lubricant flow. The coaxial arrangement of the channel portion of the particle sensor with respect to the lubricant inlet also ensures that the lubricant is guided through the channel and the channel portion of the particle sensor as uniformly as possible, i.e., without turbulence.

[0018] Alternatively, the channel portion may preferably have a coaxial offset relative to the lubricant inlet, for example to allow better integration into the structure of the drivetrain.

[0019] More preferably, the longitudinal extent of the tip detector is arranged coaxially with respect to the lubricant inlet, although here too a coaxial offset can be envisaged as a preferred alternative.

[0020] According to one exemplary embodiment, the longitudinal axis of the lubricant inlet, the channel portion of the particle sensor, and the chip detector are coaxially positioned relative to one another. By avoiding turbulence in the lubricant flow, the chip detector can extract particles from the lubricant flow and magnetically hold them in a better and more reliable manner.

[0021] According to an alternative embodiment, the particle sensor is positioned perpendicular to the lubricant inlet.

[0022] According to one exemplary embodiment, the lubricant outlet is positioned obliquely relative to the lubricant inlet, and preferably perpendicular to the lubricant inlet, and the chip detector is preferably located at the bend between the lubricant inlet and the lubricant outlet, i.e., at the deflection point of the channel.

[0023] The system for detecting the presence of particles in a lubricant flow and for analyzing particles in a lubricant flow is suitable for use in aircraft gearboxes, in particular helicopter gearboxes. In particular, the gearbox is installed in the powertrain of a vehicle, especially an aircraft. The term "aircraft" should be understood to mean a technical device used to fly in the Earth's atmosphere and transport people or goods. In the context of the present invention, "aircraft" should be understood to mean an airplane or a helicopter.

[0024] In a second aspect of the present invention, a method for detecting the presence of particles in a lubricant flow and analyzing particles in a lubricant flow is provided by a system for detecting the presence of particles in a lubricant flow and analyzing particles in a lubricant flow, the system comprising a housing having a channel for guiding the lubricant flow and fluidly connecting a lubricant inlet and a lubricant outlet, wherein particles present in the lubricant flow are detected and analyzed by a particle sensor, and magnetizable particles present in the lubricant flow are located and magnetically retained by a chip detector located downstream of the particle sensor.

[0025] According to a third aspect of the invention, a gearbox for an aircraft, in particular a helicopter gearbox, comprises a lubricant supply having a lubricant supply line for supplying a lubricant flow to at least one gearbox component to be lubricated and a lubricant return line for returning the lubricant flow, wherein a system for detecting the presence of particles in the lubricant flow and for analysing particles in the lubricant flow according to the first aspect of the invention is arranged in the lubricant return line.

[0026] The lubricant supply line and the lubricant return line are fluidly connected to a sump, in particular an oil sump or the like. The lubricant supply in the gearbox is used to lubricate and / or cool the different parts of the gearbox. The term "lubricant" should be understood to mean oil, in particular gear oil.

[0027] The system is placed at the lowest point in the gearbox where as many particles as possible are collected by gravity and removed through the lubricant return line.

[0028] The above definitions and explanations of the technical effects, advantages and advantageous embodiments of the system according to the invention as described in the first aspect of the invention apply interchangeably to the method according to the invention as described in the second aspect of the invention and to the gearbox according to the invention as described in the third aspect of the invention, and vice versa.

[0029] A preferred exemplary embodiment of the invention is described in more detail below with reference to the drawings. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a highly simplified diagrammatic representation of a gearbox according to the invention, comprising a system for detecting the presence of particles in the lubricant flow and for analyzing particles in the lubricant flow; [Figure 2] 2 shows a highly simplified diagram of the system according to the invention shown in FIG. 1; [Figure 3] 3 shows a highly simplified longitudinal section of the system according to the invention as shown in FIGS. 1 and 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0031] Figure 1 is intended to show, in a highly simplified manner, a gearbox 7 designed as a helicopter gearbox. The gearbox 7 is operatively connected for driving purposes to a drive unit (not shown here) for driving the helicopter. The gearbox 7 comprises a lubricant supply 11 for lubricating and cooling gearbox parts 12. Such gearbox parts 12 of the gearbox 7 are represented here in a highly simplified manner by rectangles. The lubricant supply 11 has a lubricant supply line 8 for supplying lubricant to the gearbox parts 12 to be lubricated and a lubricant return line 9 for returning the lubricant to an oil sump 13. The lubricant, here in the form of gear oil, is delivered by a pump 15. Disposed in the lubricant return line 9, i.e. in the lubricant flow downstream of the gearbox component 12, is a system 10 according to the invention for detecting the presence of particles in the lubricant flow and for analyzing particles in the lubricant flow, which system is configured to detect particles in the lubricant flow and to analyze them in order to draw conclusions about the wear behavior of the gearbox 7, and in particular the gearbox component 12. The system 10 is shown in Figures 2 and 3 and will be described in more detail below.

[0032] The system 10 described above is designed and configured to carry out the method according to the present invention for detecting the presence of particles in a lubricant flow and for analyzing particles in a lubricant flow, as follows: The system 10 is in communication with a monitoring unit 17 which outputs a warning signal if a threshold value is exceeded. The warning signal may be output in any desired manner and by known means.

[0033] System 10 is a sensor device having several measurement systems with different measurement principles for detecting different measurement variables. According to Figures 2 and 3, system 10 comprises a housing 1 having a channel 4 that guides a lubricant flow and fluidly connects a lubricant inlet 2 with a lubricant outlet 3. The lubricant outlet 3 is substantially perpendicular in configuration to the lubricant inlet 2 (see Figure 2), and the lubricant inlet 2 and lubricant outlet 3 in Figures 2 and 3 are represented only symbolically by arrows. Together, these arrows indicate the direction of the lubricant flow (not shown here) through channel 4.

[0034] The system 10 also comprises a particle sensor 5 as well as a chip detector 6. The particle sensor 5 is integrated into the housing 1, and the chip detector 6 is arranged so as to be removable from the housing 1. The chip detector 6 is here screwed to the housing 1.

[0035] The particle sensor 5 is configured to detect and analyze particles present in the lubricant flow. The particle sensor 5 is able to detect magnetic, magnetizable, and other particles in the lubricant flow and analyze them with respect to their type, size, and quantity. As a result, changes in the amount and composition of particles can be determined over the useful life of the gearbox component 12. The particle sensor 5 comprises a channel portion 14, which is integrated into the channel 4. According to FIG. 3, the channel portion 14 is arranged coaxially with respect to the lubricant inlet 2, by way of example.

[0036] The chip detector 6, arranged downstream of the particle sensor 5, is configured to detect and magnetically retain magnetic or magnetizable particles present in the lubricant flow. The chip detector 6 thus extracts magnetic or magnetizable particles from the lubricant flow, which passes through the chip detector 6, before the lubricant is transported out of the housing 1 and returned to the oil sump 13 via the pump 15. An oil filter (not shown here) capable of filtering out non-magnetic or non-magnetizable particles, in particular dust, may additionally be arranged upstream of the chip detector 6 and downstream of the pump 15. The longitudinal extent of the chip detector 6 is also arranged coaxially with the lubricant inlet 2. The magnetic part 16 of the chip detector 6 is arranged, for example, near a deflection point of the channel 4, where the lubricant coming from the lubricant inlet 2 and the particle sensor 5 is deflected and guided to the lubricant outlet 3. The deflection point of the channel 4 is not shown in detail here.

[0037] The particle sensor 5 and chip detector 6 communicate with a monitoring unit 17, and if a threshold is exceeded an appropriate signal is sent to the monitoring unit 17 which indicates this accordingly.

[0038] It is clearly contemplated that a plurality of such systems 10 may be disposed within an aircraft gearbox 7. In particular, two systems 10 according to the present invention may be disposed within the gearbox 7. However, it is also contemplated that more than two systems 10 according to the present invention may be disposed within the gearbox 7. Thus, the present invention is not limited to only a single system 10 within the gearbox 7. It is further contemplated that the wear of a plurality of gearbox components or groups of components may be monitored by the system 10. [Explanation of symbols]

[0039] 1: Housing 2: Lubricant inlet 3: Lubricant outlet 4: Channel 5: Particle sensor 6: Chip detector 7: Gearbox 8: Lubricant supply line 9: Lubricant return line 10: System 11: Lubricant supply unit 12: Gearbox parts 13: Oil sump 14: Channel part 15: Pump 16: Magnetic part of chip detector 17: Monitoring unit

Claims

1. 1. A system (10) for detecting the presence of particles in a lubricant flow and for analyzing particles in said lubricant flow, comprising: The invention comprises a housing (1) having a channel (4) for guiding the flow of lubricant and fluidly connecting a lubricant inlet (2) and a lubricant outlet (3), a particle sensor (5) configured to detect and analyze particles present in the lubricant flow; a chip detector (6) located downstream of the particle sensor (5) and configured to locate and magnetically retain magnetizable particles present in the lubricant flow; The system (10) further comprises:

2. 2. The system (10) of claim 1, wherein the chip detector (6) is removably attachable to the housing (1) by an interlocking and / or force-fit engagement.

3. The system (10) according to claim 2, wherein the chip detector (6) is screwed to the housing (1).

4. The system (10) of claim 1, wherein the particle sensor (5) is configured to analyze conductive particles present in the lubricant flow with respect to at least size and quantity.

5. 2. The system (10) of claim 1, wherein the particle sensor (5) comprises a channel portion (14) integrated into the channel (4), the channel portion (14) being arranged coaxially with respect to the lubricant inlet (2).

6. 2. The system (10) according to claim 1, wherein the longitudinal extension of the tip detector (6) is arranged coaxially with respect to the lubricant inlet (2).

7. 2. The system (10) of claim 1, wherein the lubricant outlet (3) is positioned obliquely relative to the lubricant inlet (2).

8. 1. A method for detecting the presence of particles in a lubricant flow and for analyzing particles in said lubricant flow by a system (10) for detecting the presence of particles in said lubricant flow and for analyzing particles in said lubricant flow, said system comprising a housing (1) having a channel (4) for guiding said lubricant flow and fluidly connecting a lubricant inlet (2) and a lubricant outlet (3), comprising: The method of claim 1, wherein particles present in the lubricant flow are detected and analyzed by a particle sensor (5), and magnetizable particles present in the lubricant flow are located and magnetically held by a chip detector (6) located downstream of the particle sensor (5).

9. Use of a system (10) for detecting the presence of particles in a lubricant flow and for analyzing particles in said lubricant flow according to claim 1 in an aircraft gearbox (7).

10. A gearbox (7) for an aircraft, in particular a helicopter gearbox, comprising: a lubricant supply section (11) having a lubricant supply line (8) for supplying a lubricant flow to at least one gearbox component (12) to be lubricated and a lubricant return line (9) for returning the lubricant flow; A gearbox (7) in which a system (10) for detecting the presence of particles in a lubricant flow and for analyzing particles in the lubricant flow according to claim 1 is disposed in the lubricant return line (9).

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