RU2469337C1 - Angular acceleration sensor with liquid rotor - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: detecting element 1 of a sensor is a cylinder 3 made from dielectric material in which metal electrodes E1, E2 are placed diametrically opposite. Exciting coils OV1, OV2, which are powered by stabilised bipolar current, are placed at the top and bottom in a plane perpendicular to the plane of the electrodes. A toroidal housing is coaxially connected to the cylinder 3. The annular cavity formed is filled with working fluid with defined electroconductivity and viscosity, e.g., water. An electrical signal which is proportional to acceleration is tapped from the electrodes and transmitted to a measuring device, at the output of which a signal proportional to angular acceleration is obtained.

EFFECT: invention simplifies the design while preserving accuracy characteristics and increases reliability owing to exclusion of movable parts.

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Description

The invention relates to measuring equipment, namely to sensors of angular accelerations, the principle of which is based on the law of electromagnetic induction.

To measure angular accelerations, devices with electromechanical sensors made in the form of paired gear disks mounted on a shaft are used. The relative displacement is proportional to the controlled value.

Known non-contact device for continuous measurement of angular accelerations [and.with. USSR No. 163446, 1964], in which the elastic element of the sensor is made in the form of a non-magnetic disk with through holes on the end surface, fastened by a ferromagnetic inertial ring with teeth interacting in the magnetic flux with the teeth of the ferromagnetic disk.

The disadvantages of this device is the low sensitivity and design complexity.

Various designs of angular acceleration sensors are known, in which mechanical effects are converted into electrical ones as a result of electrokinetic phenomena that occur when a fluid moves at the interface with a solid, for example, an electrokinetic angular acceleration sensor containing a toroidal (cylindrical) body filled with a polar liquid, for example acetone inside which at least one porous transforming wall is installed with current collecting electrodes on the sides [US 2644901, G01P 15/08, 1953].

A disadvantage of the known sensor is the low reliability, which consists in a violation of the tightness at the passage of the current leads through the wall of the housing under the action of mechanical stresses; the appearance of bubbles when the electrodes oscillate under the influence of overloads.

The electrokinetic angular acceleration sensor (patent RU No. 201851, G01P 15/08, 1990) contains a housing filled with working fluid, a porous baffle, electrodes, and a holder integrated into a modular design when used in the construction of the holder sensor. During mechanical action (rotation of the sensor around its axis), the working fluid begins to circulate, for example clockwise, through the porous septum. The flow of fluid through a porous septum as a result of electrokinetic phenomena leads to the appearance of a potential difference at the electrodes. When the direction of rotation of the sensor changes, the direction of fluid movement changes to the opposite, which accordingly changes the sign of charges on the electrodes.

A disadvantage of the known sensor is its low reliability, due to the complexity of its manufacturing technology and a sufficiently large number of components.

Closest to the proposed invention is an angular acceleration sensor with a liquid rotor (US 3520196, G01P 15/08, 1970), in which angular acceleration is converted into an electrical signal. This device contains a toroidal (cylindrical) casing filled with a non-conductive fluid, performing the function of a fluid rotor (inertial element). As a sensitive element (sensor), an electromechanical system is used, consisting of a permanent magnet, a movable inductor, mechanically connected to the valve, one end of which is placed in the gap of the toroidal housing and reacts to the angular movement of fluid in the housing. The other end of the shutter is used to convert angular displacement into an electrical signal proportional to angular acceleration.

The disadvantages of this device is the presence of a movable inductor, which reduces the reliability of the device, as well as the complexity of the design, due to the large number of precision parts, and, therefore, high cost.

The objective of the invention is to simplify the design while maintaining accuracy characteristics, increasing reliability due to the lack of moving mechanical parts.

This is achieved by the fact that in an angular acceleration sensor with a liquid rotor containing a sensing element and a toroidal (cylindrical) housing filled with liquid and performing the function of a liquid rotor, the sensitive element is a cylinder filled with a working fluid made of a dielectric material in which diametrically oppositely located metal electrodes in contact with the liquid in a plane perpendicular to the plane of the electrodes; excitation windings are installed above and below Ia, feeds the bipolar constant current, toroidal body connected coaxially to the cylinder sensitive element to form an annular cavity filled with hydraulic fluid, the presence of angular acceleration of the electric signal proportional to its value, is removed from the electrode sensing element and supplied to the measuring device.

The invention is illustrated by drawings.

Figure 1 shows the proposed angular acceleration sensor, consisting of a sensing element 1 and a toroidal (cylindrical) body 2; figure 2 is a sensor of angular accelerations, a top view, where ω is the direction of action of angular acceleration; figure 3 shows a functional diagram of a device with which the measurement of angular acceleration is carried out.

The sensitive element (sensor) 1 contains a cylinder 3, E1, E2 - electrodes; OB1, OB2 - field windings; V is the fluid velocity relative to the cylinder; IU - measuring device; f is the output signal proportional to the acceleration of fluid motion; I _app. - stabilized supply current (figure 3).

The sensing element 1 is a cylinder 3 made of a dielectric material in which metal electrodes E1, E2 are diametrically opposed. In the plane perpendicular to the plane of the electrodes, the field windings OB1, OB2 are mounted above and below, energized by a bipolar stabilized current. The toroidal housing 2 is connected coaxially to the cylinder 3 of the sensing element 1. The annular cavity thus formed is filled with a working fluid with a certain electrical conductivity and viscosity, for example, water (Fig. 1).

The liquid acts as an inertial element - a liquid rotor.

The angular acceleration sensor operates as follows.

With mechanical action - the presence of angular acceleration relative to the measuring axis Y (figure 2), the movement of the annular cavity relative to the inertial element (fluid inside the annular cavity) occurs.

According to the law of electromagnetic induction, an EMF is induced in a fluid moving in a magnetic field:

e = -B · l · V,

where is the magnetic induction;

l is the distance between the electrodes;

V is the fluid velocity.

An electrical signal proportional to the acceleration is removed from the electrodes E1 and E2 and fed to the measuring device IU (figure 3). A signal proportional to angular acceleration is output from the output of the measuring device. When the direction of angular acceleration ω (Fig. 2) changes, the direction of fluid motion changes and, accordingly, the polarity of the output signal changes at the output of the measuring device.

Thus, during mechanical action (rotation of the sensor relative to the measuring axis), the working fluid will begin to circulate inside the annular cavity and, according to the law of electromagnetic induction, EMF is induced in the fluid moving in the magnetic field, an electrical signal proportional to the acceleration is removed from the electrodes and fed to the measuring device, and a signal proportional to angular acceleration is output from the output of the measuring device.

Distinctive features of the invention are the absence of movable precision parts, simplicity of design, low cost.

Claims (1)

An angular acceleration sensor with a liquid rotor, comprising a sensing element and a toroidal (cylindrical) body filled with liquid and performing the function of a liquid rotor, characterized in that the sensitive element is a cylinder filled with a working fluid made of a dielectric material in which contacting with metal electrodes in a plane perpendicular to the plane of the electrodes; excitation windings are installed above and below pityvaemye bipolar constant current, toroidal body connected coaxially to the cylinder sensitive element to form an annular cavity filled with hydraulic fluid, the presence of angular acceleration, an electric signal proportional to its value, is removed from the electrode sensing element and supplied to the measuring device.

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