SU1442856A1 - Device for checking condition of bearings - Google Patents

Abstract

The invention relates to a control and measurement technique and can be used for non-destructive testing of assemblies, in particular rolling bearings. The goal is to increase the control accuracy by reducing the errors associated with fluctuations of the contact resistance of the current collector. A current is induced from the alternator 10 through the first transformer (T) 6 in the shaft 3 and the controlled bearing 1. The magnitude of the current is monitored by T 7 and the current detector (D) I. The voltage drop on the monitored bearing I is removed from the current collector 13 and fed to the voltage input D 12. To the first input of the ratio meter 14, the output voltage of the current D p is supplied directly, and to the second output voltage D 12 of the voltage through a temperature-dependent divider. The ratio meter 14 forms a digital equivalent of the ratio of the voltage drop across the bearing to the current flowing through it and transmits it to the recorder 15. The current pickup is 5 S &

Description

-

ttT lifar

Fy.}

144

The nickname has been transferred to the high resistance circuit to measure the voltage drop across the bearing. The condition of the rolling bearing is monitored in relation to the voltage drop across it to the magnitude of the current flowing through the black. Each

one

The invention relates to a control and measurement technique and can be used in the destructive testing of assemblies, in particular rolling bearings.

The purpose of the invention is to improve the control accuracy by reducing the errors associated with fluctuations of ne --- transient resistance of the current collector.

Figure 1 shows the scheme of the proposed device; in Fig.2, the equivalent circuit of the device.

The device for monitoring the state of bearings contains a controlled rolling bearing I, the inner ring 2 of which is fixed on shaft 3 and the outer 4 in housing 5, first 6 and second 7 transformers, magnets 8 and 9 of which are coaxial with shaft 3, the latter being one of the windings of each of the transformers 6 and 7, the alternator 10, the output of which is connected to the primary winding of the first transformer 6, the current detector 11, the input of which is connected to the secondary winding of the second transformer 7, the detector 12, for example, Jenin, input to first connected to the shaft 3 through the current collector 13, sequentially connected to the I4 ratio meter and the recorder 15, the first input of the 14 ratio meter is connected to the output of the current detector P directly, and the second to the output of the voltage detector 12 via AC 5 - through temperature dependent resistor 17.

The current detector 11 contains a single-action amplifier 18, the non-inverting input of which is connected to the housing 5, and the inverting input - to the secondary winding of the second transformer 7 directly and to its output

from magnetic circuits T 6 and 7 are made in the form of two half-rings, on one of which is placed the primary winding T 6 or the secondary winding T 7, which ensures that both T are fixed on line 3 without disassembling the unit. 2 Il.

Sh

20

| 5 25 th

Q

five

through a parallel connected resistor 19 n diode 20.

The voltage detector 12 contains an operational amplifier 21, the non-inverting input of which is connected to the current collector 13 directly, and the inverting input - to the housing 5 via a resistor 22 and to its output via a parallel-connected resistor 23 and a diode 24.

For the convenience of fixing transformers 6 and 7 on the shaft 3 without disassembling the assembly, each of the magnetic cores 8 and 9 is made in the form of two half-rings, one of which is the primary winding of the transformer 6 or the secondary winding of the transformer 7.

The device works in the following way.

The alternator 10 generates a voltage of a predetermined frequency (on the order of 0.1-1 MHz) and an amplitude that is applied to the primary winding of the first transformer 6. Under the action of an electromotive force induced in the secondary winding of the first transformer 6, which is shaft 3, monitored bearing 1, housing 5 and uncontrolled elements electrically connected between shaft 3 and housing 5, for example, the second gear-pair bearing and others, a current I begins to flow, the value of which is determined by the complex resistance Zp controlled bearing and complex resistance Z uncontrollable elements.

The magnitude of the current I flowing through the shaft 3 and the monitored bearing 1 is controlled by the second transformer 7, the electromotive force on the secondary winding of which is

E where L

i (JMI jnULfll,

inductance of the primary winding of the transformer 7; n is the number of turns in the secondary winding of the transformer 7; M - mutual induction. The input electromotive force and output voltage U, operational amplifier 18 of current detector II are related by relations

W: W. and -i v

j, and, and. . about, ,

OS

de L is the inductance of the secondary winding of the transformer 7, equals 2.

and

 OS

on p

the voltage at the inverting input of amplifier 18; the gain of the amplifier 18 without feedback ;, the resistance of the feedback equal to zero at a negative half-wave of the output voltage of the amplifier 18 and Z K, d. where R, and the resistance value of the resistor 19, with a positive half-wave.

Since the gain modulus is 18 amplify

Zoc

TO

01

1 +

 V

Ilul

13

over the entire operating frequency range, for 35 constant co c i being current detector 1

and,

The voltage drop at the monitored bearing 1 through the current collector 13 is applied to the high-resistance non-inverting input of the amplifier 2 of the voltage detector 12. The output voltage of this amplifier is

g

IZ,

og

in

de K, is the gain of the amplifier 21 without feedback; contact resistance of the current collector 13; the input impedance of the amplifier 21 at the non-inverting input;

OS g

the resistance value of the resistor 22 between the inverting input of the amplifier 21 and the housing 5;

feedback resistance equal to zero at a negative half-wave at the output of amplifier 21 and

2: R

ti

ss where rjj value

Since the ratio

resistances of the resistor 23, for a positive half wave, are usually always performed

/ Co.

 1 +

Zoc „

 R

 Z

22

FOR CONSTANT component of the signal input meter can be recorded

one

on 1A

second about t but-

g

i | (,

V.2i R. ,,

25

thirty

Where

R

&

And r

17

the coripc values are the phenomena of the constant resistor 1 6 and temperatures. but a dependent resistor 17 respectively.

The meter 14, made in the form of an analog-digital integrating converter, forms the digital equivalent of the ratio

i, / u,. p ..Li- | i «i L |„ 1 tV 56, l (

nineteen

Cg

40

45

35

And passes it to the input of the registrar 15 for registration.

Thus, the recorded value Zj5 with an accuracy of up to a constant multiplier, which is easily taken into account during the initial setup of the device, is equal to the complex resistance Z of the controlled rolling bearing 1.

The temperature dependence of the electrical conductivity of the bearing lubricant is corrected by an appropriate choice of the resistance values of resistors 16 and 17 and the temperature and coefficient of resistor 17.

The value of the control error is equal to the known device.

pr z, j

/ 2.

 And it really amounted to 10-15% of the knock when using metal klk of mercury current collectors, drops to

About Z, / Zgx

ag g

Claims (1)

Claim A device for monitoring the condition of bearings, comprising a housing with a drive shaft for fixing and rotating a controlled bearing, an alternating current generator, a current collector for supplying alternating current to a controlled rolling bearing, a temperature-dependent resistor, θ permanent resistor, recorder, first and second transformers, whose magnetic circuits coaxial with the shaft, and the shaft is one of the windings of each transformer, distinguishing— ”with the fact that, in order to improve the accuracy of control by reducing errors associated fluctuations in the transition resistance of the current collector is 15 ka, it is equipped with a current detector, a voltage detector and a voltage ratio meter, the primary winding of the first transformer is connected to the output of the alternating current generator 20, the secondary winding of the second transformer is connected to the input of the current detector, the input of the voltage detector is connected to the shaft through current collector, the first input of the relationship meter is connected to the output of the current detector, and the second to the output of the voltage detector through a constant resistor and with an external m ring bearing through the temperature-dependent D · 30 ican, relationship yield meter is connected to the registrar. FIG. g I Compiled by V. Puchinsky editor I. Gornaya Tehred M. Khodanich Corrector N.Korol Order 6376/39 Circulation 847 Subscription VNIIIPI of the USSR State Committee for Inventions and Discoveries 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and printing company, Uzhhorod, st. Project, 4.