RU2488122C1 - Contactless sensor of rotor rotation speed and position - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: device comprises a fixed stator and a movable rotor with permanent magnets. The stator is made in the form of a circular magnetic conductor with two circular half-windings with a pole division equal to π, inside of which coaxially there is a magnetic rotor installed on a bearing, made as salient-pole with one pair of poles. At the same time the stator and rotor are installed in the cylindrical body.

EFFECT: simplified design and expanded possibilities of a device, production of double voltage at an output and galvanic isolation.

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Description

The invention relates to measuring electrical engineering, in particular to non-contact sensors of speed of rotation and position of the rotor, and is intended for use in electric motors of various types to determine the speed of rotation and position of the rotor in a resonant electric drive of rotational motion.

A known speed measurement sensor (RF patent No. 2150114, publ. 27.05.2000), comprising a housing, a rotor installed in it in the form of a multi-pole magnetic ring mounted on a shaft, and a magnetic field sensor fixed in the housing stationary with a gap relative to the multi-pole magnetic ring and separated from it by a sealed partition. One end of the rotor shaft is mounted in the housing on a thrust bearing, the transmission speedometer drive performs the function of supporting the second end of the rotor shaft. A compression spring is installed between the drive and the multi-pole magnetic ring.

The disadvantages of this device are the complexity of manufacture and the inability to adjust the output voltage.

A known speed sensor (patent of the Russian Federation No. 2190856, publ. 10.10.2002).

The rotation speed sensor includes an annular multipolar magnet located on the drive shaft, a magnetic induction comparator with an element sensitive to changes in the magnetic field located at the outer cylindrical surface of the multipolar magnet, and a permanent magnet located in the region of the sensing element, which allows adjusting the parameters of the output signal sensor by changing the magnitude of the induction of a constant magnetic field of displacement in the region of the sensitive element by moving permanent magnet and / or its rotation around its axis.

The disadvantages of this device is the need to use a multi-pole magnet and a magnetic induction comparator, which complicates and increases the cost of the sensor design.

Also known is the position sensor of the rotor of the electric motor (RF patent No. 2357348, publ. 27.05.2009), taken as a prototype. The ED rotor position sensor contains a fixed stator rigidly connected to the stator of an electric motor, magnetically sensitive elements, for example, Hall sensors or magnetoresistors, a rotor made of magnetically insulating material and kinematically connected to the rotor of an electric motor, a ferromagnetic disk with slots, and two annular permanent magnet magnetized axially. In this design of the sensor, two permanent magnets common to all sensitive elements are used, which are rigidly fixed to the rotor shaft together with a magnetic disk. The field of permanent magnets extends to the Hall sensitive elements through a magnetic disk and an air gap, as a result of which the sensitivity of the sensor to displacements of the sensitive elements relative to the magnets, as well as to the heterogeneity of the permanent magnets, is reduced.

The disadvantages of this sensor is the need to maintain the specified accuracy in the manufacture of a magnetic disk with slots, as well as the difficulty in replacing magnetically sensitive elements, such as Hall sensors or magnetoresistors, located on the stator of the rotor position sensor ED.

The technical result of the invention is to simplify the design and expand the capabilities of the device, including obtaining double voltage at the output and galvanic isolation.

The technical result is achieved by the fact that the non-contact sensor of rotational speed and rotor position, containing a fixed stator and a movable rotor with permanent magnets, is equipped with a cylindrical body with a cover in which a stator is made, made in the form of a magnetic circuit with two circular half-windings with pole division equal to π, inside which coaxially mounted on the bearing mounted magnetic rotor, made explicitly with one pair of poles.

A cylindrical housing with a cover protects the sensor from the effects of negative external factors.

The design of the stator magnetic circuit with two half-windings with pole division π allows to obtain various output voltages depending on the connection scheme (in series or in parallel), and also to have two galvanically isolated sources of control voltage depending on the number of windings used.

A magnetic rotor with permanent magnets, made explicitly with one pair of poles, provides the creation of an electromagnetic field for the operation of the device.

The sensor is illustrated by drawings, in which Fig. 1 shows a diagram of a non-contact sensor for rotational speed and rotor position, in Fig. 2 shows the shape of the output voltage from a non-contact sensor, in Fig. 3 shows a non-contact sensor without a cover, and Fig. 4 shows a non-contact sensor in an assembly , Fig. 5 shows a magnetic circuit with two annular semi-windings, Fig. 6 shows embodiments of explicit pole rotors with permanent magnets for a proximity sensor, Fig. 7 shows methods for connecting stator windings without stroke sensor, depending on the requirements.

The device comprises a cylindrical housing 1 with a cover 4, an annular magnetic circuit 2 with two annular half-windings with pole division equal to π, and a magnetic explicit pole rotor with permanent magnets with one pair of poles 3, a sliding bearing 5 and the gap between the stator and rotor 6 installed in the housing 1 A magnetically polar pole rotor 3 of the sensor is placed on the shaft of the electric motor with a combination of the longitudinal axis of symmetry of the rotors of the sensor and the electric motor.

The proximity sensor has 6 leads: "AX", "BY", "CZ", where the working windings "AX" and "BY" are the terminals of the semi-windings along the X axis, and "CZ" are the conclusions of the semi-windings along the Y axis. Fig.7 "*" indicates the beginning of the winding. When connecting the winding, as shown in Fig. 7 a) a voltage is formed equal to the voltage of each of the semi-windings, while reliability is increased. When implementing the circuit of Fig. 7 b), the output voltage doubles. Harmonically isolated windings are obtained when connected according to the scheme of Fig. 7 c).

When the sensor is operating, an electromagnetic field arises between the magnetic circuit 2 with two annular half-windings with pole division equal to π, and a magnetic explicit pole rotor with one pair of poles 3. At the output of the sensor, we obtain a voltage that is regulated by changing the connection scheme of the windings. When the rotation of the rotors of the electric motor and the speed sensor and the position of the rotor are stopped, the output signal will be zero.

A non-contact sensor of rotation speed and rotor position can be used in the implementation of closed-loop control systems for electric drives of rotational motion used in drilling complexes to provide continuous resonant self-oscillations to implement a method of excitation and regulation of autoresonant vibrations in an electric drive of rotational motion (RF patent No. 2410826 C1 ) The oscillation range of the rotor of the electric motor of the reverse-rotational movement, at which a non-contact sensor of rotation speed and rotor position can be used, reaches 180 °.

In addition, the sensor can be used in wiring systems of an automated electric drive with an unbalanced rotor, providing the formation of signals of the rotor position (Fig.7a) at the outputs 4.1-3.2) and the amplitude value of the speed at each revolution (Fig.7 conclusions 5, 6).

Figure 2 presents the waveform, which shows the shape of the voltage from a non-contact speed sensor and the position of the rotor U _DC , the amplitude value of which is U _DC = 4V. At the same time, the intersection of the output axis voltage curve corresponds to the setting of the rotor of the explicit pole motor in the extreme position.

Thus, when simplifying the design, the capabilities of the sensor expand.

Claims (1)

A non-contact rotational speed and rotor position sensor comprising a fixed stator and a movable rotor with permanent magnets, characterized in that the stator is made in the form of an annular magnetic circuit with two annular semi-windings with pole division equal to π, inside of which a magnetic rotor is made coaxially on the bearing, made explicitly pole with one pair of poles, while the stator and rotor are placed in a cylindrical housing with a cover.

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