DD155927A1 - CAPACITIVE MEASUREMENT OF OIL TEMPERATURE DISTRIBUTION IN SLIDING BEARINGS - Google Patents

Abstract

The invention relates to the field of berührungslosen temperature measurement in plain bearings of turbines, pumps, motors o. Ae. The invention provides the possibility to determine the distribution of the oil temperature in the sliding bearing without changing the hydrodynamic Stroemungsverhaeltnisse. The object, which is solved by the invention, is the contactless temperature measurement of moving liquids. The essence of the invention is that by the electrical separation of the upper and lower bearing shell the system upper bearing shell - wave - lower bearing shell is interpreted as veraenderlicher, temperature and Orttsabhaengiger capacitor and that by measuring the capacity of this capacitor and the geometric parameters of a Determination of the oil temperature distribution is possible. The possible fields of application of the invention are the field of contactless temperature measurement of moving electrically insulating liquids, which are located between at least two mutually standing, mutually stationary or mutually moving electrically conductive bodies.

Description

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The invention of _f

a) Title of the invention :.

Capacitive measurement of oil temperature distribution in plain bearings

b) Field of application of the invention:

Me invention relates to the field of non-contact temperature and displacement measurement in plain bearings of turbines, pumps, motors oa ..

c) Characteristic of the known technical solutions:

The known technical solutions have the crucial, denden lack that is disturbed in the "measurement of the oil temperature of the hydrodynamic flow and thus Meßfehler generated. The introduction of probes (thermocouples, resistance thermometers oa) just in the narrowest critical lubrication gap is out of this Another possibility is to drain oil via a drain valve at the time of measurement. The effluent oil passes directly to a thermocouple. The pressure buildup is disturbed by the drain at the time of measurement, so that the measurement result is subject to a key error. The measurement methods mentioned also allow only a punctiform measurement and are technologically difficult to implement.

./1/ Ivanov, V.l .: Sposob zamera terrnoparani temperatury. masljanogo sloja opor skol'senija

, Vestnik Masiiiostroenija (1978) 10,

S.31-32

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d) Aim of the invention:

The object of the invention is, without changing the hydrodynamic flow conditions in the lubrication gap to allow the measurement of the oil temperature distribution in plain bearings. Thus, the prerequisites for the application of technical diagnostics in plain bearings are created. In particular, conclusions can be drawn with regard to the thermal stress of the white metal layer.

e.) Explanation of the essence of the invention:

The technical problem that is' solved by the invention, is the non-contact measurement of the oil temperature distribution in plain bearings. The lack of the previously known solutions are that only a punctiform measurement of the oil temperature at one or more points in the plain bearing in case of disturbance of the hydrodynamic flow conditions possible v / ar. The measurement of the oil temperature distribution offers the possibility of examining the energy conversion in the plain bearing and the load of the white metal layer in more detail. The invention is characterized by:

- The complete insulation, (electrical) of the upper and lower bearing shell of a sliding bearing, the distance between upper and lower bearing shell remains constant;

- The measurement of the capacity between the upper and lower bearing shell by the upper and lower bearing shell are provided with one electrical connection;

- The measurement of the position of the shaft with two angular displacement transducers.

Thus, the measuring capacity C and the position of the shaft within the upper or lower bearing shell is known at any time of the measurement. The indication of the temperature distribution is possible by means of a calculation method. • Generally, for the capacitance C of a plate capacitor, the equation:

2 2 6 6 77

The capacity of the upper bearing shell is in series with the capacity of the lower bearing shell. Parallel thereto are the transverse capacities that arise at the bearing surfaces between the shells. For the calculation, the capacity of the upper or lower bearing shell is divided into a finite number of partial capacities. In the case of an integral calculation for the total capacity C, e>

C ₀ Ά

SSL.

(2) ι (3)

Co'Cu __

1 + CCs (ff ₀ )

^ Z-df

W) C _Q + Cu ^L »

Since = const, the integral is not closed solvable. The relationship between c and T can be determined experimentally for the respective type of oil. For the calculation, a numerical method is used. In a microprocessor processing unit, the characteristic data = = ((T) and the weighting characteristics C / C = f (e, oo) are stored. During the measurement, the measured capacitance C and the static displacements of the values S and Sp measured with the two angular displacement transducers and the value for CO are stored by a rotational speed measuring device. From the measured static displacements, the distances d. the . Partial capacities calculated and determines the value for the eccentricity e. ' Thereafter, the weighting of the capacity shares takes place as a function of e and ΙΟ. From an initially arbitrary approach for the temperature parameters T _Q and b. will be out:

-τ- Λ T {= L _G

⁴ "22 6 6 77

a temperature distribution over χ. calculated. About the. Characteristic £ ~ £ (T) is the determination of the to

- belonging to P-. Together with the calculated d. results in ι ι

of the

the capacity of the lower bearing shell C to

The capacity of the upper bearing shell is considered as a first approximation as constant, ie with a constant temperature distribution. From the thus calculated capacity C _u and from the weighting in which the capacity C _{Q is} determined, the total capacity C is calculated and

If the calculated and measured capacitance do not match, then the temperature parameters T _Q and b- must be varied until the error is less than o. If the error is less than 6 , the calculated T the temperature distribution in the lower bearing shell is. The oil temperature in the upper bearing shell is considered constant and can be determined in a numerical calculation method from equation (2). The essence of the invention consists in the fact that by the electrical separation of the upper and lower bearing shell system upper bearing shell - wave - lower bearing shell as a variable, temperature and location-dependent capacitor v / ird and that by measuring the capacitance of this capacitor and the geometric Parameter is a calculation of the £ \ values and thus the T. values or the oil temperature distribution is possible. ,

f) embodiment:

An embodiment is shown in Figures 1, 2 and 3. Figure 1 shows the structure of the modified journal bearing. Figure 2 shows the feeding of the required measured quantities to the microprocessor processing unit. Figure 3 shows a possible processing in form 'A flow chart for the determination of the oil temperature distribution in the TvEPV.

Claims (7)

1. The upper and lower bearing shell of a plain bearing are completely isolated from each other electrically. 2. The distance between the upper and lower bearing shell "is constant. 2 6 6 7 7 Erfindunrsanspruch Capacitive dimensioning of the oil temperature distribution in sliding bearings is characterized in that: 3 · The upper and lower bearing shells are provided with an electrical connection. 4. The capacity between upper and lower bearing shell is measured. , 5. The measurement of the position of the shaft with respect to the bearing shell by two angular displacement sensor is carried out. 6. Connect the capacitance measured between the upper and lower bearing shells and the Keßsignale for the position of the F / elle within the bearing shell according to the manner indicated in the embodiment of Figure 2 with each other. -. 7. The temperature distribution is calculated by the manner given in the embodiment of Figure 3 way by electronic means. For this ..xj pages drawings