RU173573U1 - CAPACITIVE DIFFERENTIAL SHAFT ANGLE SENSOR - Google Patents

Abstract

The utility model relates to measuring technique and can be used to measure the angle of rotation of the shaft of a mechanical device. Sensor capacitances are made in the form of conductive plates on the dielectric disks of two stators, containing two plates made in the form of sectors of conductive material and connected to the terminals for connection to measuring circuit. Both stators are stationary in the sensor housing. The rotor is rigidly connected with the rotary shaft and is located coaxially with the stators so that when the shaft is rotated in one direction or another, some containers increase and others decrease. The rotor is made in the form of a disk made of double-sided foil dielectric, on both sides of which are made conductive foil plates in the form of a sector, connected by a jumper and facing towards two stationary stators. The technical result achieved by the implementation of the claimed solution consists in increasing the steepness of the output characteristic sensor achieved through the use of a decoupling capacitor. 5 ill.

Description

The utility model relates to measuring technique and can be used to measure the angle of rotation of the shaft of a mechanical device.

Capacitive differential sensors of the angle of rotation of the shaft are known, which are two containers constructed structurally in such a way that when the shaft is rotated in one direction or another, one of the containers increases and the other decreases.

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

A known capacitive sensor for measuring angular displacements (RF patent for the invention No. 2289785, MPK7 G01B 7/30, IV Minaev, GB Soldatov, publ. 12/20/2006), containing two coaxially mounted and fixed stator plates between which a rotor is mounted, mounted on a rotating shaft. A continuous annular metal element is made on one stator plate, and an annular metal element in the form of three sectors is made on the other stator plate. The rotor is made in the form of a sector of the disk of a solid, preferably dielectric, material.

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

Closest to the proposed device in technical essence is a capacitive differential sensor of the angle of rotation of the shaft (RF patent for utility model No. 145255, MPK7, G01B 7/30, Podlevsky N.I., Malofienko SG, published September 10, 2014) made in the form of conductive plates on the dielectric disks of two stators, between which the rotor is coaxially arranged, made in the form of a disk of a double-sided foil dielectric, on one side of which a conductive foil plate is made in the form of a sector facing two n movable plates of the first stator of the sensor, and on the other side of the rotor conductive plate is formed as a ring, facing towards the fixed annular second stator plate.

This sensor does not give advantages in increasing the steepness of the output characteristic of the sensor when using a decoupling capacitor formed by ring-shaped plates of the rotor and the second stator, since the magnitude of such a decoupling capacitor does not depend on the angle of rotation of the shaft.

In the proposed device, the specified technical result (increasing the steepness of the output characteristic of the sensor) is achieved through the use of a decoupling capacitor. It is formed by a second stator containing two plates made in the form of sectors of conductive material on a dielectric disk and connected to the terminals for connection to the measuring circuit, and the rotor side facing the second stator and made in the form of a conductive foil plate in the form of a sector moreover, the conductive sectors on both sides of the rotor are interconnected by a jumper. With this design of the decoupling capacitor, its value will also depend on the angle of rotation of the shaft, which will significantly increase the steepness of the output characteristic of the sensor.

The device capacitive differential sensor of the angle of rotation of the shaft shown in the figure.

A capacitive differential sensor of the angle of rotation of the shaft consists of a first stator 1, a rotor 2, a second stator 3, a rotary shaft 4 and a housing 5, (Fig. A). 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.

On the stator 1 (Fig. A), on the rotor side, two plates 7 and 8 (Fig. B) are made in the form of sectors of conductive material on a dielectric disk, forming, through a dielectric gap, together with the rotor plate 9 (Fig. C) capacitors C1 and C2 (Fig. g). The plate 9 of the rotor 2, made in the form of a disk of a double-sided foil dielectric, has the shape of a sector and faces the stator 1 so that in the neutral position of the rotary shaft 4 forms equal overlap areas through the dielectric gap with the plates 7, 8 of the stator 1, i.e. . equal capacities C1 and C2 (Fig. g).

On the second side of the rotor 2, a foil plate 10 is made in the form of a sector similar to sector 9, facing the stator 3. The rotor plates 9 and 10 are electrically connected to each other by a jumper 11.

On the side of the stator 3 facing the rotor 2, plates 12, 13 (Fig. E) are made in the form of two sectors similar to plates 7, 8 of conductive material on a dielectric disk, which with the plate 10 of the rotor 2 through the dielectric gap in the neutral position of the rotary shaft 4 form equal overlap areas, that is, equal decoupling capacitances C3 and C4, and decoupling capacitance C3 connected in series with capacitance C1, and decoupling capacitance C4 with capacitance C2, ensuring equilibrium of capacities. When the shaft rotates in one direction or another (± α) from the neutral position, one of the containers (for example C1, C3) increases, and the other two (C2, C4) decrease (or vice versa), thereby forming a signal change that has a large slope (sensor sensitivity) than with a constant value of decoupling capacity.

From the fixed contacts of the plates 7, 8, 12, 13 of the capacitors C1, C2, C3 and C4, the outputs are the wires - Outputs. 1, Exit 2, Exit 3 and Exit. 4, designed to connect to the inputs of a signal processing circuit that converts the output signals of the shaft angle sensor into a convenient (required) form.

The device operates as follows.

When the shaft 4 is in the neutral position, the rotor 2 and the stators 1, 3 with their plates 7, 8, 9, 10, 12 and 13 through the dielectric gap, as a result of the symmetrical mutual arrangement, create equal capacities C1, C2, C3, C4, which, in turn, creates an equilibrium state at the inputs of the signal processing circuit.

With the angular displacement of the shaft 4 in one direction or another by an angle ± α, the plates 9 and 10 of the rotor 2 will move relative to the plates 7, 8, 12 and 13 of the stators 1 and 3, violating the symmetrical mutual arrangement of the plates, which will lead, for example, to an increase in C1 , C3 and to a decrease in C2, C4 (or vice versa), while creating a mismatch of signals at the inputs of the signal processing circuit.

Claims (1)

A capacitive differential shaft angle sensor containing two stationary stators and a rotor mechanically coupled 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 a dielectric disk and connected to the terminals for connection to the measuring circuit, and the rotor is made in the form of a disk of a double-sided foil dielectric, on one side of which is made a conductive foil plate in the form of a sector facing two plates of the first stator, characterized in that the second stator also contains two plates made in the form of sectors of conductive material on a dielectric disk and connected to the terminals for connection to the measuring circuit, and the other side the rotor facing the second stator is made in the form of a conductive plate of foil in the form of a sector, and the conductive sectors on both sides of the rotor are interconnected by a jumper.

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