SU1101695A1 - Device for measuring torque and power - Google Patents

Abstract

A DEVICE FOR MEASURING THE TORQUE AND POWER, containing a shaft with an elastic section, at the ends of which two disks are installed with tags evenly spaced around the circumference, two pulse markers sensors, installed stationary, shaft speed sensor, electronic key, constant voltage source, a switch for two positions, three resistors, an indicator and a capacitor, which is connected in parallel and, to the distributor, one input of which is connected through one resistor to one terminal of the second resistor, the second terminal Is connected to the input of a switch, one position of which is connected to a source of direct voltage, and the other to a shaft speed sensor, and the outputs of the pulse sensors of the tags are connected to the corresponding inputs of the electronic key, characterized in that neither a torsion shaft oscillation, a shaft rotation direction sensor, a second constant voltage source, and two equivalence circuits are inserted into it, the electronic key is equipped with a second output, and the switch is entered in the second direction, one position jcofopo is associated with the shaft rotation direction sensor, the other with the second source of constant voltage, and the input of the second direction of the switch is connected to one input of both equivalence schemes, the other inputs of which are connected to the corresponding outputs of the electronic key, and outputs - respectively, with one SP output of the second resistor and with the second input of the indicator, to which a switch input is connected through a third resistor, and the pulse sensors of the tags are installed from aimnym angular displacement. equal to P J +

Description

The invention relates to load measurement technology and can be used to measure average values of torque and power of an arbitrarily rotating shaft of various propulsion systems.

A device for measuring torque and power, which contains an elastic shaft, two measuring discs attached to the shaft ends, two sensors for reading tags and-and, measuring circuit tlj

The disadvantage of this device is low accuracy.

The closest to the technical essence of the invention is a device for measuring torque and power, which contains a shaft with an elastic section, at the ends of which two disks are mounted with tags evenly spaced around the circumference, two pulse mark sensors installed permanently, a shaft rotation frequency sensor electronic key, DC voltage source, two position switch, three resistors, an indicator and a capacitor, which are connected in parallel to the indicator, one input of which through one resistor It is connected to one output of the second resistor, the second output of which is connected to the input of the switch; one position of which is connected to the constant voltage source and the other to the rotation-shaft frequency sensor, with the outputs of the pulse sensors of the tags connected to the corresponding inputs of the electronic switch 23.

A disadvantage of the known device, STB is low accuracy, due to false positives of the measuring circuit in the event of a torsional vibration of the shaft.

. The purpose of the invention is to improve accuracy by reducing the effect of torsional vibrations of the shaft.

This goal is achieved due to the fact that the device for measuring torque and power, containing a shaft with an elastic section, at the ends of which two disks are mounted with labels evenly spaced around the circumference, two pulse markers sensors, installed stationary, shaft rotation frequency sensor , electronic key, DC voltage source, two position switch, three resistors, an indicator and a capacitor, which is connected in parallel to the indicator, one input of which is connected to one through one resistor The output of the second resistor, the second output of which is connected to the input of the switch, one position is connected to a constant voltage source, and the other is connected to the shaft rotation frequency sensor, the outputs of the pulse markers are connected to the corresponding inputs of the electronic key, the shaft rotation direction sensor is inserted, the second constant voltage source and two equivalence schemes, with the electronic key equipped with a second output, and the second direction is entered in the switch, one position of which is associated with a shaft rotation direction sensor, the other with a second constant voltage source, and a second direction input of the switch is connected to one input of both equivalence schemes, the other inputs of which are connected to the corresponding outputs of the electronic key, and the outputs respectively to one output of the second resistor and with the second input of the indicator, to which the resistor is connected to the switch input, and the pulse sensors of the tags are installed with a mutual angular displacement equal to

3- n (2n - 1) - | -,

d

de 0 is the angle of mutual displacement of the pulse sensors of the tags, counted in a plane parallel to the plane of the disks; ti О, tl, t2, ... j angle between adjacent markers on disks mutual angular displacement

drives with no load on the shaft.

FIG. 1 shows a block diagram of a device for measuring torque and power J in FIG. 2 shows section A-A and B-B in FIG. 1 (scheme of regulations - V 1ki pulse tag sensors); in fig. 3 - amplitude-time diagrams explaining the device operation in the mode of torque measurement.

The device for measuring the torque, thrust momentum and power contains the first 1 and second 2 measuring disks, a portion of the elastic shaft 3, pulse sensors 4 and 5 marks, electronic key b, first 7 and second 8 equivalence wires, first 9 and second 10 matches , indicator 11, capacitor 12, three DC resistors 13-15, a shaft rotation frequency sensor 16, a shaft rotation direction sensor 17, interlock unit 18, constant voltage sources 19 and 20, switching. 21 types of measurements.

Measuring discs 1 and 2, mounted on the ends of the elastic shaft 3,

serve to linearly convert the twist angle of a portion of the shaft 3 to an angular shift between the marks on the disks.

Pulse sensors 4 and 5 marks register shafts of marks passing by them during rotation by forming a short pulse at the output.

The electronic key 6 is made on a trigger with separate inputs and generates a non-inverting output signal proportional to the duration of the phase shift of the pulse from sensor 5 relative to the pulse from d 1 sensor 4,

CxeMJ 7 and 8 of equivalence, each of which implements the output of a logical function of the form

h

.t V 5., where a, b are the corresponding initial

signals;

designed to control the inversion of signals from the output of the electronic key 6.

CxevK 9 and 10 matches, each of which implements a logic function of the form

p2 "-

b matching input

where a. signals, are designed to turn off the indicator 11 when the signaling device of the zero signal is received from the output of the device 18 and are performed on the NAND logic gates with an open collector output.

Resistor 13 and capacitor 12 form an averaging circuit and isolate the constant component of the voltage across the measuring diagonal of the bridge.

Indicator 11 serves to measure the magnitude and sign of a constant voltage component in the measuring diagonal of the bridge.

Resistors 14 and 15 of the same resistance form the two upper arms of the bridge, in which the two lower arms are formed by the collector outputs of coincidence circuits 9 and 10.

The shaft rotational frequency sensor 16 serves to convert the shaft rotational frequency into a proportional direct current voltage of constant polarity and performs amplitude modulation of the voltage in the measuring diagonal of the bridge in the mode of power measurement on the shaft. Output tension. The sensor 16 of the frequency of the shaft vrasheni at the nominal clock of the shaft rotation is equal to the voltage 19. The implementation of the TeiKoro device is possible, for example, on the basis of a waiting multivibrator and a low-pass filter.

The shaft rotation direction sensor 17 generates at the output a signal of a logical unit when the shaft rotates in a direction conventionally taken as positive, and the signal of a logical zero when the shaft B rotates in the opposite direction. This device can be implemented, for example, on the basis of a DC tachogenerator with a polarity determination circuit of its output voltage. Blocking node 18 generates a logical one-output signal at the output if the shaft rotation frequency exceeds the tieKOTOpoe specified threshold

five . a value below which the shaft is considered stationary, and a signal of logical zero otherwise. This device can be implemented, -. vano for example based on selector

0 duration.

The constant voltage source 19 serves to power the measuring bridge in the torque measurement mode, and the constant voltage source 20 to create a voltage level of the logical unit that is fed to the inputs of the equivalence circuits 7 and 8 in the measurement mode power.

0

In addition, the pulse sensors 4 and 5 tags are installed with a mutual angular displacement (figure 2)

et

(2p

five

where f is the angle of displacement of the measuring disks with no load on the shaft,. ± 1, ± 2 ...; p is the angle between adjacent marks on the measuring disk.

A device for measuring torque and power works as follows.

five

If the top rotates at a frequency that exceeds a predetermined threshold of block 18, then it produces a high logic signal at the output

level 1.

0

Let the leading edge of the voltage pulse U4 from the pulse sensor 4 marks sets the electronic key 6 to a state with a positive voltage on the non-inverting

5 output, and the leading edge of the voltage pulse Uc from the pulse sensor 5 marks returns the electronic key 6 to the state with zero voltage at the output output of the Fig 3; D, Ug): When the unloaded shaft is inserted, the signals from the pulse sensors 4 and 5 marks are phase shifted by the Ti angle due to their initial setup with relative estimate d - –jr, a multiple of half the pole division / 3/2. In this case, the electronic key b switches with a duty cycle equal to two, and the duration of the positive pulses at its non-inverting output f; is equal to the duration of the positive pulses at the inverting output t, i.e. T (, T (, 3). inputs of the equivalent circuits 7 and 8. Let the shaft rotate at a frequency W o, then the output of the shaft rotation direction sensor 17 produces a high-logic level voltage and, 1, in the torque measurement mode for the second inputs and 8 equivalence levels through switch A reader of a kind of measurement. With this equivalence circuits 7 and 8, the input signals from the dongle 6 are not inverted, and the duration of the positive pulses at their outputs is equal to b, respectively. b These pulses arrive at the first inputs of the circuits 9 and 10. Coincidence. the inputs are supplied by the blocking node 18, the duration of their positive output signals is 9 S, respectively. Thus, in the measuring diagonal of the bridge, where the resistor 13 and the capacitor 12 are connected, therefore, alternates p rectangular voltage with it whose value Ud. chDv. (6-I) where and is the supply voltage of the measuring bridge; Cd is the coefficient of proportionality. In this case, the indicator readings are proportional to the voltage U J1Г-i м ЧF n (6-Ть). - coefficient of proportionality. Since when f is unloaded, f (6 then and 0). If you change the direction of rotation, the picture of the phase shifts of the signals from the sensors does not change and still remains equal to XI and, similarly to the case, you can A high logic level of the output of the second source 20 of a constant voltage is applied to the second inputs of circuits 7 and 8 of variability, therefore the output signals are analogous to t - Effective when measuring torque at and 0 if the shaft is not loaded n, the average value of the voltage in the measuring diagonal of the bridge and the indications of the indicator 11 remain zero. It is easy to show that in the general case, in the mode of torque measurement, the indication of indicator 11 is equal.). and in the mode of power measurement.) where 1 / is the angle of twist of the shaft; and - a control logic signal supplied to the second inputs of the equivalence circuits 7 and 8 through a measurement switch 21 from the shaft rotation direction detection device 17 in the torque measurement mode and the second constant voltage source 20 in the power measurement mode; K (, is a constant coefficient; UJ is the shaft rotation frequency. In addition, in the proposed device, for any combination of shaft rotation directions and torque, the following equalities are observed: Sign (U, J Sign CM) Sign (U ..) Sign ( Ne) .e. The direction of deflection of the arrow of the indicator 11 corresponds to the sign of the torque or power on the shaft in any direction of the shaft. The proposed device provides an increase in the measurement accuracy when torsional oscillations waa. Let the shaft rotate clockwise and perform torsional vibrations with amplitude V , at the same time, the mean torque can be equal to zero (). Let also the frequency of the pulses from sensors 4 and 5 of the amnom mark exceed the frequency of the torsional oscillations, which usually doettigetch in such devices by selecting the appropriate number of labels on measuring discs for a given

the frequency range of the shaft rotation and the constant time of the R13C12 circuit are many times longer than the period of torsional vibrations.

In the proposed device, when the indicator is shown 11, the preprior of the angle is H, and

the angle (- W), taking into account the sign, therefore, dp of the average readings is K-true.

)about

Thus, the proposed device provides a significant increase in the accuracy of measurements when there are shaft torsional vibrations / which allows its use in installations for which strong shaft torsional vibrations are unavoidable (for example, dp measurements of average values of torque and power on the propeller shafts of ships with engines of internal combustion).

H

-f

.but

h

//////

M70,

ill

% 4JLU |,

W,

a-

l / j-th

ft

Of

Ul

0

On

Claims (1)

DEVICE FOR MEASURING TORQUE AND POWER, containing a shaft with an elastic section, at the ends of which are two disks with marks evenly spaced around the circumference, two pulse mark sensors installed stationary, ·. shaft speed sensor, electronic key, constant voltage source, two-position switch, three resistors, indicator ^; and a capacitor that is connected in parallel with the indicator, one input of which is connected through one resistor to one terminal of the second resistor, the second terminal of which is connected to the input of the switch, one position of which is connected to a constant voltage source, and the other to a shaft speed sensor, and the outputs pulse mark sensors are connected to the corresponding inputs of the electronic key, characterized in that, in order to increase accuracy by reducing the influence of torsional vibrations of the shaft, the sensor is directed into it shaft rotation, a second constant voltage source and two equivalent circuits, while the electronic key is equipped with a second output, and the second direction is entered into the switch, one position of which is connected with the shaft rotation direction sensor, the other with the second constant voltage source, and the second direction switch input connected to one input of both equivalence circuits, the other inputs of which are connected to the corresponding outputs of the electronic key, § and the output, respectively, with one output of the second resistor and with a second indicator input, to which a switch input is connected through a third resistor, and the pulse mark sensors are installed with mutual ”angular displacement. equal to οί = y + (2n + 1) - y, where d- is the angle of mutual displacement of the pulse mark sensors measured in a plane parallel to the plane of the disks; h = 0, + 1, + 2, ...; d - the angle between adjacent marks on the disks; γ - mutual angular displacement of the disks in the absence of load on the weigh. SU „, 1101695