CN1155819C

CN1155819C - Method for detecting metal filings in lubricating oil

Info

Publication number: CN1155819C
Application number: CNB991171365A
Authority: CN
Inventors: 刘峰璧
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-11
Filing date: 1999-10-11
Publication date: 2004-06-30
Anticipated expiration: 2019-10-11
Also published as: CN1291721A

Abstract

The present invention relates to a method for detecting metal abrasive dust in lubricating oil, which is characterized in that lubricating oil containing metal abrasive dust flows into a passage, of which the peripheral wall is provided with at least one part composed of opposite metal pole plates insulated mutually. When the lubricating oil passes between the metal pole plates, changes of the capacitance between the pole plates are detected. Compared with the prior art, the present invention has the advantages of high detection accuracy, and does not need attracting the abrasive dust by magnetic force. When nonferromagnetic abrasive dust is detected, premagnetization procedures are omitted, and detection processes are simplified.

Description

A kind of method that detects the metallic rubbing pairs degree of wear

Technical field

The present invention relates to a kind of method that detects metal filings in the lubricating oil, can be used for monitoring by the residing state of wear of friction pair of the containing metal friction pair element of oil lubrication.

Background technology

Wear process in the machine parts generally experiences three phases, i.e. running-in wear stage, normal wearing stage and sharp wear stage.The feature in running-in stage generally is that rate of depreciation is descending, progressively reaches normal wearing stage; The rate of depreciation substantially constant of normal wearing stage; Arrive sharp wear after the stage rate of depreciation increase sharply, friction pair is about to lose efficacy.Therefore, can infer that by the variation that detects abrasive dust amount in the lubricating oil friction pair grinds residing state of wear.The method of metal filings in the existing detection lubricating oil, be to make it be trapped on the glass sheet with the magnetic attraction abrasive dust when making the lubricating oil that contains abrasive dust flow through glass sheet or glass tube or on the glass tube walls, by measuring the penetrability of these glass sheet or glass tube, detect the existence of abrasive dust simultaneously; Or these glass sheet or glass tube are taken off, with microscope, electron scanning mirror or other method it is observed.List of references is seen " ferrous specturm technique principle and the application " that China Machine Press published in 90 years.This method that detects abrasive dust with the glass sheet of surveying the deposition abrasive dust or glass tube penetrability, be subjected to the restriction of effective light-receiving area of the beam cross-section size of light emitted or photosensitive device, when the lubricating pipe cross sectional dimensions is only cun big than the light beam of light source xsect, can not directly provide the information of the contained whole abrasive dust amounts of lubricating oil in the pipeline.Secondly, pass through because the single-layer metal abrasive dust can blocking light, thus transmittance can not reflect metal filings on the deposition glass sheet or glass tube walls along the overlapping accumulation of light path whether or the thickness of sedimentary deposit.Thereby this detection method degree of accuracy is lower.In addition, owing to need to adopt magnetic force that abrasive dust is deposited on glass sheet or the glass tube walls, therefore to the also magnetization earlier of nonferromagnetic abrasive dust.

Summary of the invention

The purpose of this invention is to provide and a kind ofly need not to adopt the magnetic attraction abrasive dust, and the method for metal filings in the degree of accuracy higher detection lubricating oil.

The present invention is achieved in that and makes the lubricating oil that contains metal filings flow into a passage, the perisporium of described passage has at least a part to be made of insulated from each other and relative metal polar plate, when lubricating oil passes through between the metal polar plate, detect electric capacitance change between pole plate, because the electric capacity between pole plate changes with the size of what and abrasive dust particle of metal filings amount in the lubricating oil, when promptly more or particle is big when abrasive dust, electric capacity between pole plate is bigger, otherwise it is then less, therefore according to detected electric capacitance change situation, can estimate the content status of metal filings in the lubricating oil, thereby infer the residing state of wear of friction pair.For example can test in running-in wear stage, normal wearing stage and sharp wear stage respectively the pair of metal friction pair in certain machine in advance.Obtain the electric capacity between the pole plate corresponding, as with reference to value, when actual detected, electric capacity and reference value that the scene records are made comparisons with this with each stage.Can judge the wear condition that constitutes this friction pair.The present invention is not only because can directly detect the entrained abrasive dust of lubricating oil that is positioned at monoblock pole plate surface area, and because abrasive dust can directly influence the size of electric capacity between pole plate along the accumulative total yardstick of the direction of an electric field direction of pole plate (promptly perpendicular to), so detect the degree of accuracy height than existing methods.On the other hand, owing to need not deposit abrasive dust, therefore need not to use the magnetic attraction abrasive dust.

The invention has the advantages that: 1, because this method has improved the degree of accuracy that detects metal filings in the lubricating oil, therefore can infer friction pair state of wear of living in more accurately, the machine parts that is about to lose efficacy is accomplished timely replacing, avoid the loss that mechanical disorder caused of losing efficacy and causing because of kinematic pair; 2, for the non-ferromagnetic metal abrasive dust, saved magnetization step in advance, testing process is simplified.

Description of drawings

Fig. 1 is a principle sketch of the present invention;

Fig. 2 is the embodiment 1 of passage of the present invention;

Fig. 3 is the A-A cut-open view of Fig. 2;

Fig. 4 is the embodiment 2 of passage of the present invention;

Fig. 5 is the B-B cut-open view of Fig. 4.

Embodiment

Principle of the present invention as shown in Figure 1, form a passage 2 between metal polar plate 1a, the 1b insulated from each other, when the lubricating oil 3 that has metal filings is flowed through this passage, with the electric capacitance change situation between testing circuit detection pole plate 1a, the 1b, can infer the situation of contained metal filings in the lubricating oil.Testing circuit can adopt the electronic circuit of existing various measurement electric capacity sizes, as the bridge detection circuit of forming by testing capacitance and fixed capacity or resistance, and the frequency modulation metering circuit of testing capacitance and inductance composition or the like, perhaps directly use existing electric capacity to measure instrument.The capacitor that above-mentioned metal polar plate and therebetween the lubricating oil medium of flowing through are constituted is as a testing capacitance element in these circuit, when between pole plate during electric capacitance change, from the variation of the output signal parameter (as oscillation frequency, voltage etc.) of circuit, can detect the variation of electric capacity between pole plate.

With the metal polar plate is the concrete structure of the passage of constitutive requirements, can be with reference to the structure of relevant capacitance type sensor in the prior art, and according to the actual conditions flexible design.Electrode thickness is littler in principle, and edge effect is littler, and can reduce because of ambient temperature changes and make how much foots of pole plate cun and the contingent variation of relative position.Polar plate bracket also should have stable performance except that the tool certain mechanical strength, therefore generally select for use temperature coefficient little good with the physical dimension long-time stability.And material with high insulation resistance, low moisture absorption and high surface resistance.Elaborate with embodiment below.

Embodiment one

Referring to Fig. 2,3, metal polar plate is metal plate 4a, the 4b of pair of parallel, and they are for being plated in AL ₂O ₃Silver layer on ceramic wafer support 5a, the 5b.Ceramic wafer support 5a, 5b are fixedly arranged in respectively in housing member 6 inner groove opposite 7a, the 7b, and housing member 6, metal polar plate 4a, 4b just surround a cuboid passage 8 like this.This passage joins by threaded hole 9a, 9b and the lubricating pipe of upper/lower terminal, and the lubricating oil in the machine is flow through between two-plate 4a, the 4b.Housing member 6 can be made with teflon.

In order to prevent two-plate 4a, 4b, can lay a layer insulating 10a, 10b respectively on the surface of two-plate 4a, 4b by the metal filings short circuit.This insulation course can be made with teflon.

Embodiment two

Referring to Fig. 4,5, metal polar plate is a pair of coaxial cylinder shape sheet metal 11a, 11b.They are for being plated in AL ₂O ₃Silver layer on cylinder 12a, the 12b.AL ₂O ₃Cylinder 12a, 12b are installed with respectively in groove 14a, the 14b of housing member 13 inside.Housing member 13 can be made with teflon, form the passage 15 that the transversal section is an annular between two-plate 11a, the 11b, this passage is by the circumferential a series of hole 16a of upper/lower terminal, 16b, and threaded hole 17a, 17b on the housing member 13 are communicated with lubricating pipe.With embodiment one in like manner, can respectively lay a layer insulating 18a, 18b on the surface of two-plate 11a, 11b.

The quantity of metal polar plate is not subjected to the restriction of above two embodiment, and how right can be provided with, and it is several right for example can be provided with along oil flow direction, and how right perhaps be provided with around the perisporium of passage, can also be many to coaxial cylinder shape sheet metal or the like.

Claims

1, a kind of method that detects the metallic rubbing pairs degree of wear, it is characterized in that: make the lubricating oil of metallic rubbing pairs flow into a passage, the perisporium of described passage has at least a part to be made of insulated from each other and relative metal polar plate, when lubricating oil passes through between the metal polar plate, detect electric capacitance change between pole plate, infer the residing state of wear of metallic rubbing pairs according to detected electric capacitance change situation.

2, the method for claim 1 is characterized in that described metal polar plate is one or more pairs of parallel metal plates.

3, the method for claim 1 is characterized in that described metal polar plate is one or more pairs of coaxial cylinder shape sheet metals.

4, as claim 1,2, one of 3 described methods, it is characterized in that being covered with a layer insulating on the surface of metal polar plate.