RU188545U1 - CAPACITIVE DIFFERENTIAL SENSOR OF ANGLE OF ROTATION OF A SHAFT - Google Patents

Abstract

Use: to measure the angle of rotation of the shaft mechanical device. The essence of the utility model is that a capacitive differential angle sensor shaft contains two stator and a rotor, mechanically connected to the rotary shaft of the sensor and located coaxially between the first and second stator through dielectric gaps, the first stator contains two plates made in the form of sectors conductive material on the dielectric disc and connected to the leads for connection to the signal processing circuit, and the rotor is made in the form of a disc of double-sided foil dielectric, one side of which is made of a conductive foil plate in the form of a sector facing the two plates of the first stator, and on the second side of the rotor there is a conductive plate of foil in the form of a ring facing the annular plate of the second stator, the rotor plates being electrically interconnected, and the plate of the second stator is connected to the output for connection to the signal processing circuit, while between the back sides of the dielectric disks of the first and second stator and the sensor housing are located rifle elements, clamping disks of stators with freedom of movement along the axis of rotation of the shaft to the sensor rotor disk and providing a plane-parallel, maximum approximation of the conductive plates of the stators and the rotor to each other, while the disks of the stators and the sensor rotor are made of dielectric material with the required precision by pressing , on whose planes conductive plates are applied by gluing metallized films with a conductive surface inwards, and a dielectric surface outside , Wherein the conductive plate on the metallized films formed photoresist method and disposed on the stator and rotor coaxially. Technical result: providing the possibility of improving the accuracy of measuring the angle of rotation of the shaft. 1 il.

Description

The invention relates to the measurement technique and can be used to measure the angle of rotation of the shaft of the mechanical device.

Known capacitive differential sensors angle of rotation of the shaft, which are two containers, constructed constructively in such a way that when you turn the shaft in one direction or the other, one of the containers increases and the other decreases.

These two capacities are included in the sensor signal processing circuit (VA Atsyukovsky. Capacitive differential displacement sensors. Automation library, issue 12. Gosenergoizdat, M., L., 1960, pp. 20-22).

Known capacitive sensor for measuring angular displacements (RF patent for the invention No. 2289785, IPC 7, G01B 7/30, Minaev IV, Soldatov GB, published 12/20/2006, Byul. 35), containing two coaxially installed and fixed plates of the stator, between which is placed a rotor mounted on a rotating shaft. On one plate of the stator there is a continuous ring-shaped metal element, and on the other plate of the stator an annular metal element is made in the form of three sectors. The rotor is made in the form of a sector of a disk made of solid, preferably dielectric, material.

This sensor due to the excessive complexity of electronic signal processing, as well as a small order of capacitance values, due to the relatively large air gap due to the constructive need to position the rotor dielectric sector between the stator plates of the rotor dielectric disc does not give advantages when used in electromechanical devices with limited angles of rotation of the shaft less than ± 90 °).

The closest to the proposed device to the technical nature is a capacitive differential shaft angle sensor (RF patent for utility model No. 162923, MPK7, G01B7 / 30, Podlevsky N.I., Malofyenko S.G., Antonov A.S., published 27.06 .2016, Bull. No. 18), made in the form of conductive plates on dielectric disks of two stators, between which the rotor is coaxially arranged, made in the form of a disk of double-sided foil dielectric, on one side of which a conductive plate of foil is made in the form of a sector, reversed I on the side of two fixed plates of the first stator of the sensor, and on the other side of the rotor there is a conductive plate in the form of a ring facing the fixed ring-shaped plate of the second stator, while spring elements are located between the back sides of the dielectric disks of the first and second stator and the sensor body Stator discs to rotor disc through dielectric spacers.

This technical solution does not offer any advantages in increasing the accuracy of the sensor output signal due to the non-uniformity of the dielectric gap between the conductive plates of the stators and the rotor, due to the technological variation of the thickness and flatness of the discs made of sheets of foil fiberglass.

The technical result of the proposed utility model is to improve the accuracy of measuring the angle of rotation of the shaft of the mechanical device.

In the proposed device, the technical result is achieved by using disks of stators and a rotor, made with the required accuracy of a dielectric material, by pressing, on whose planes conductive plates are applied, by gluing metallized films with a conductive surface inwards, and a dielectric surface outward, while conductive plates on metallized films made in a photoresistive way and are located on the stators and the rotor coaxially.

The device of a capacitive differential sensor for the angle of rotation of the shaft is shown in the design diagram (Fig. 1a, b, c, d).

A capacitive differential shaft angle sensor consists of the first stator 1, the rotor 2, the second stator 3, the rotary shaft 4 and the housing 5, (Fig. 1a). The stators 1, 3 are located in the housing 5 coaxially with the axis of rotation of the shaft 4 and the rotor 2 rigidly connected with the shaft 4 of the mechanical device 6. The stators 1, 3 and the rotor 2 are made in the form of discs made of a dielectric material, for example, by pressing with the required accuracy, depending on the problem of measuring the angle.

On the plane of the stator 1 (Fig. 1a), on the rotor side, the foiled film 7 (Fig. 1b) is pasted with a conductive side inward, on which, in a photoresistive way in the form of sectors, conductive plates 8 and 9 (Fig. 1b) are made, forming, through the dielectric gap, together with the conductive plate 10, made in the form of a sector on the foiled film 11 (Fig. 1c), which is pasted with the conductive side inwards on the plane of the rotor 2, capacitors C1 and C2 (Fig. 1a). In the neutral position of the rotary shaft 4, plates 8, 9 and 10 form equal areas of overlap of the conductive sectors, i.e. equal capacitances C1 and C2, the ratio of which varies in one direction or another, depending on the direction of movement of the shaft from the neutral.

On the second plane of the rotor 2, facing the stator 3, the foiled film 12 (Fig. 1c) is pasted with a conductive side inward, on which an annular plate 13 is made, and the conductive plates 10 and 13 are electrically connected by a jumper 14. The conductive plate 13 of the rotor 2 through a dielectric gap forms with a conductive plate 15 made on the foiled film 16 (Fig. 1c) in the form of a ring, which is pasted with a conductive side inwards on the plane of the stator 3 (Fig. 1a), facing the rotor 2, decoupling the capacitor C3. Conductive plates 8, 9, 10, 13 and 15 are located on the stators and the rotor coaxially relative to the axis of the shaft 4 and as close as possible to each other by pressing the stators 1, 3 to the rotor 2 by means of springs 17, 18 (Fig. 1a) located between the backs of the stators 1, 3 and the sensor housing 5.

From the fixed contacts of the conductive plates 8, 9 and 15 (capacitors C1, C2 and C3) of the sensor, the outputs of signals O 1, O 2 and O 3 are connected to the inputs of the processing circuit 19, which has a known solution that converts the output signals of the sensor into a convenient form.

The device works as follows.

When the sensor shaft 4 is in the neutral position, the rotor 2 and the stators 1, 3 with their conductive plates 8, 9, 10, 13 and 15 through the dielectric gaps, as a result of a symmetrical mutual arrangement, create equal capacitances C1 and C2, and decoupling capacitance C3 of constant value , independent of the angular position of the rotor 2, which, in turn, creates an equilibrium state at the inputs of the processing circuit 19 of the sensor output signals.

When the angular movement of the shaft 4 in one direction or another at an angle of ± α, the conductive plate 10 of the rotor 2 will move relative to the plates 8, 9 of the stator 1, breaking their symmetrical mutual arrangement, which will lead, for example, to an increase in capacitance C1 and a decrease in capacitance C2 ( or vice versa) and will create a mismatch of signals at the inputs of the processing circuit 19, which converts it into a signal proportional to the angle of the shaft movement.

Performing disks of stators 1, 3 and rotor 2 of increased accuracy in thickness and flatness of dielectric material, by pressing and applying conductive plates 8, 9, 10, 13, 15 on the working surfaces of the discs by gluing metallized films 7, 11, 12, 16 with the conductive surface inward, and the dielectric surface outward allows to improve the accuracy of conversion of the angle of movement of the shaft 4 of the sensor.

Claims (1)

A capacitive differential shaft angle sensor containing two stators and a rotor mechanically connected to the sensor rotary shaft and located coaxially between the first and second stators through dielectric gaps, the first stator containing two plates made in the form of sectors of conductive material on the dielectric disk and connected with leads for connection to the signal processing circuit, and the rotor is made in the form of a disk of two-sided foil dielectric, on one side of which an electrical conductor is made Foil plate in the form of a sector facing the two plates of the first stator, and on the second side of the rotor there is a conductive plate made of foil in the form of a ring facing the ring plate of the second stator, the rotor plates being electrically interconnected, and the plate of the second stator connected to the output for connection to the signal processing circuit, while between the back sides of the dielectric disks of the first and second stator and the sensor housing there are spring elements clamping the stator disks in, having freedom of movement along the axis of rotation of the shaft, to the rotor disk of the sensor and providing a plane-parallel, maximum approximation of the conductive plates of the stators and the rotor to each other, characterized in that the disks of the stators and the rotor of the sensor are made of a dielectric material with the required precision by pressing on the plane which conductive plates are applied by gluing metallized films with a conductive surface inwards, and a dielectric surface outwards, while the conductive layer us to metallized films made photoresist method and disposed on the stator and rotor coaxially.

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