SU853436A1 - Device for measuring shaft torque - Google Patents

Description

(54) DEVICE FOR MEASUREMENT

one

The invention relates to the field of force-measuring equipment and can be used to measure the variable and constant components of the torque on a rotating shaft in installations where the frequency of the pulse component of the moment is a multiple of the frequency of rotation of the shaft and has the character of a steady process.

The known device for measuring the torque on the shaft, containing two pulse sensors spaced apart along the shaft, the comparison unit, the measuring circuit and the indicator do not provide the required measurement accuracy.

The closest in technical essence and the achieved result to the present invention is a device for measuring the moment on the shaft, containing two disks with labels associated with the extreme sections of the base shaft section, sensors for reading the tags from the amplifier; j 1-formers, a forming unit timestamp intervals and measuring circuit 2.

The disadvantage of this device is the low accuracy of the measurement of the variable component and the extreMoNT on the shaft.

maximum values of torque in the steady state operation of the device.

The aim of the invention is to increase the measurement accuracy.

 This goal is achieved due to the fact that a signal selection block consisting of series-connected

10 clock generation, sampling start circuit and coincidence circuit, the output of which is directly connected with the measurement circuit and through the sample end circuit with the second circuit input

15 of the start of the sampling, the third input of the sampling start circuit and the second input of the coincidence circuit are associated with the output of the time interval generation unit, and the input of the formation circuit

20 sync pulses are associated with the output of one amplifier former.

Figure 1 shows the block diagram of the device, figure 2 - time diagram of the operation of the device.

25

A device for measuring the torque on the shaft (Fig. 1) contains an elastic shaft 1, with rigidly mounted on it .. measuring discs 2 with equal peripheral marks and sensors for reading marks 3 and 4, connect

Inputs with corresponding amplifiers mi-converters 5 and b, the outputs of which are connected with the inputs of the unit for airtime 7.

The signal selection unit consists of a sync pulse shaping circuit 8, a coincidence circuit 9, an on-sampling circuit 10, and a sampling end circuit 11. The input of the sync pulse shaping circuit 8 is connected to the output of one of the driver amplifiers; coincidence circuit 9. The output of the coincidence circuit 9 is related to measure-. The primary circuit 12 and, through the end sampling circuit I, with the second input of the circuit, sample 10, and the second input of the comparison circuit 9 and the third input of the beginning circuit, selected 10, are connected to the output of the time interval forming unit 7,

The device works as follows.

The resilient shaft 1 is affected by a steady-state torque, containing a constant and a variable component. The frequency of the variable component of torque M is a multiple of the angular frequency of rotation of shaft 1 (Fig. 2, M). Under the action of a constant component of the torque, the spatial mutual arrangement of the measuring disks 2 changed by a constant value proportional to the applied post-constant component of the torque. Along with a time-constant displacement of the disks 2, the angular displacement between them changes under the action of the variable component of the moment. When the shaft 1 rotates, the output of the sensors 3 and 4 appear harmonic voltages shifted in phase (Fig.2, IT | , U ;,) by an angle proportional to the current torque. The signals from the outputs of sensors 3 and 4 are fed to amplifiers 5, b that convert them, for example, in a square-wave voltage with fronts rigidly connected with the moments of harmonic voltage transition at the output of sensors 3 and 4 through zero. The outputs of the formers 5 and b control the inputs of the unit for forming time intervals 7, the output of which produces square pulses with a duration proportional to the applied torque and inversely proportional to the speed of rotation of the shaft 1, FIG. 2 a).

The duration of each of these pulses contains three components; component determined by the initial installation of disks 2; component proportional to the magnitude of the fixed constant moment component and component varying from pulse to pulse

and proportional to the variable torque component.

From the output of the circuit 6 to the input of the formation circuit of the sync pulse 8, a square wave voltage is applied. A sync pulse is generated at the output of circuit 8. (Figure 2, 6 with a repetition frequency equal to the angular frequency of rotation of shaft 1. The time position of the sync pulse is rigidly related to a specific phase and the magnitude of the variable component of the moment. The same hard time relationship exists between the output clock pulses block 7, therefore, the pulses at the output of block 7, located at the same time distance from the sync pulse, characterize the same vase and, consequently, the magnitude of the torque (Fig. 2a).

To separate the pulses from the output of block 7, which are at the same distance from the sync pulse, a signal selection block is inserted into the device.

Depending on the frequency of the variable component of the torque, the number of teeth, the number of measurements to be performed on the period of the variable component of the torque, the number of pulses transmitted to the input of the measuring circuit 12 may be different. The number of these pulses in a pack (sample) will determine the accuracy of the piecewise linear approximation of the measured moment.

The moment of the beginning of the passage of pulses from block 7 to the measuring SCHEME 12 is determined by the sample start circuit 10, to the input of which a clock pulse arrives from circuit 8. From the moment the clock pulse arrives from circuit 8, circuit 10 starts counting the number of pulses from block 7 to the third input of circuit 10 Depending on the program in the circuit 10, when a pulse arrives (Fig. 2, a), the output of the circuit 10 generates a pulse failing the coincidence circuit 9 (Fig. 2, c). The pulses from the output of block 7 begin to pass through the circuit 9 to the measuring circuit 12 .. (Fig. 2, d).,

The pulses from the output of circuit 9 are also fed to the counter input of the circuit of the end of the sample 11. Upon the arrival of the% pulse from block 7 (FIG. 2, a), whose number is embedded in the program of circuit 11, the output of circuit 11 produces a signal (FIG. ) received at the second input of the circuit 10, which closes the coincidence circuit 9 and the signals from block 7 to block 12 do not arrive. Schemes 10 are being prepared for the new work cycle.

Thus, the measuring circuit 12 receives bursts of pulses from block 7, carrying information about

current torque. This information is converted by circuit 12 into a quantity proportional to the torque acting on the shaft in time intervals rigidly related to the angle of rotation of the shaft, for example, by determining the constant component of the voltage sequence of the pulses entering the input of circuit 12.

The use in the device for measuring the moment on the shaft of the signal selection unit will improve the accuracy of measurement of the variable component and the extreme values of the torque.

Claims (2)

Invention Formula A device for measuring the torque on the shaft, containing two disks with tags associated with the extreme sections of the base shaft section, sensors for reading tags with amplifier-formers, a time interval shaping unit and a measuring circuit, characterized in that, in order to improve the accuracy measurement unit, a signal selection unit is inserted in it, consisting of series-connected sync pulse shaping circuits, a sampling start circuit and a coincidence circuit, the output of which is directly connected to the measuring circuit and through the circuits end of the sample to a second input of the circuit o the beginning of the sampling, the third input of the sampling beginning circuit and the second input of the coincidence circuit are associated with the output of the time interval generation unit, and the input of the formation circuit 5 sync pulses are associated with the output of one amplifier former. Sources of information taken into account in the examination of 20 1 USSR Author's Certificate No. 558186, cl. G 01 L 3/10, 13.08-.75. 2. Frolov L.B. Torque measurement. M., Energie, 1967 p.47-48 (prototype). 25 -four- 853436 h with: U with with with ez-- ) ) ) s c s WITH ) с с: с ) with: h | ) sch t with with with ) with: and with g (