Device for determining the direction of shaft rotation

Abstract

FIELD: measurement technology.SUBSTANCE: device for determining the direction of rotation of a shaft comprises a Hall sensor and a control unit for processing signals received from the Hall sensor, wherein the device comprises a disk secured on the shaft, on the end surface of the disk there are blind holes in which permanent magnets are installed, wherein the blind holes form three groups, wherein the first group comprises one hole, the second group two holes, the third group three holes, the outer holes of each group are at an equal distance from the outer holes of adjacent groups, and the distances between the holes in the second and third groups are the same.EFFECT: increase in the accuracy of determining the direction of shaft rotation.3 cl, 1 dwg

Description

[0001] The invention relates to the field of measurement technology and can be used in devices for which determining the direction of rotation of a shaft is critically important, for example, in the oil industry and for machines with propellers in the shipping industry.

[0002] A device for measuring the rotational speed of a variable-pitch propeller shaft is known from the prior art (RU Patent No. 174921 for Utility Model, published 10.11.2017, IPC G01P 3 / 487), adopted as a prototype, comprising a track with variable physical properties along its surface, applied to the outer surface of the shaft, a recording sensor located with an air gap relative to the shaft in the area of ​​the track installation, and a sensor signal processing unit. The track is made in the form of at least two discrete flat magnetic strips of varying lengths, applied along the shaft generatrix with different distances between them.

[0003] The disadvantage of the above-mentioned device is the inability to correctly determine the direction of rotation of the shaft due to the principle based on measuring the distances between magnetic strips, which, when rotating in opposite directions, form a repeating sequence of two signals.

[0004] The technical result of the present invention is to improve the measurement accuracy of the device by limiting the rotation of the shaft in the incorrect direction.

[0005] The technical result is achieved in that the device for determining the direction of rotation of the shaft contains a Hall sensor and a control unit for processing the signals received from the Hall sensor, wherein the device contains a disk fixed on the shaft, on the end surface of the disk there are blind holes in which permanent magnets are installed, wherein the blind holes form three groups, where the first group contains one hole, the second group - two holes, the third group - three holes, the outer holes of each group are at an equal distance from the outer holes of adjacent groups, and the distances between the holes in the second and third groups are the same.

[0006] Also, the Hall sensor is located with an air gap in relation to the installation area of ​​the permanent magnets.

[0007] In addition, the disk is made of non-magnetic material.

[0008] The drawing shows the device for determining the direction of rotation of the shaft:

[0009] 1 - shaft;

[0010] 2 - disk;

[0011] 3 - permanent magnet;

[0012] 4 - Hall sensor;

[0013] 5 - control unit.

[0014] The device for determining the direction of rotation of the shaft contains a Hall sensor 4 and a control unit 5 for processing the signals received from the Hall sensor 4, wherein the device contains a disk 2 fixed on the shaft 1, on the end surface of the disk 2 there are blind holes in which permanent magnets 3 are installed. The blind holes form three groups, where the first group contains one hole, the second group - two holes, the third group - three holes, the outer holes of each group are at an equal distance from the outer holes of the adjacent groups, and the distances between the holes in the second and third groups are the same.

[0015] Hall sensor 4 is located with an air gap relative to the installation area of ​​permanent magnets 3.

[0016] Disc 2 is made of non-magnetic material.

[0017] The device operates as follows.

[0018] When shaft 1 rotates, with disk 2 fixed to it, the first, second and third groups of permanent magnets 3 move in the area of ​​action of Hall sensor 4, forming a sequence of signals, which is recorded in control unit 5. Calculation of rotation speed and analysis of the sequence occurs in control unit 5. The direction of shaft rotation is determined by the generated sequence of signals from three groups of permanent magnets 3. An example of sequence formation is carried out as follows:

[0019] 1. The direction of rotation is clockwise if the number of signals of the third group of permanent magnets 3 is greater than the number of signals of the second group of permanent magnets 3;

[0020] 2. The direction of rotation is counterclockwise if the number of signals of the first group of permanent magnets 3 is less than the number of signals of the second group of permanent magnets 3.

[0021] The distances between permanent magnets in groups must be chosen so that a signal sequence can be formed. If the T1 distance is too small, the signal from the permanent magnet group will merge into a single long signal during rapid rotation, which is unacceptable, as it will prevent subsequent analysis of the signal sequence. Therefore, the T1 distance should be chosen so that a clear signal sequence is formed at the required rotation speed.

[0022] The mandatory presence of a third group of permanent magnets allows for the determination of the direction of rotation at any time (in the case of a design with two groups, the signal will be repeated during rotation without the ability to determine the direction of rotation). This expands the functionality of the proposed technical solution: determining the direction of shaft rotation.

[0023] Adding additional magnet groups with four or more holes is impractical, as it requires additional resources and will not affect the final technical result. Depending on the disk diameter, additional permanent magnet groups (more than three) will reduce the distance between the holes in each group. Furthermore, it is highly likely that the signals from different magnets will be more difficult to detect, as they will merge into one long signal. Therefore, installing three groups is optimal, as the third signal already allows determining the direction of shaft rotation.

[0024] The device was designed using a HAL506UA Hall sensor as the magnetosensitive element. The disk housing the magnets was made of a non-magnetic material—D16 duralumin—to maintain the magnetic field from the magnets. The disk's outer diameter, according to the device's layout, was 123 mm and 15 mm thick. Three groups of magnets (the first group with one magnet, the second group with two magnets, and the third group with three magnets) of the Ch36R type with a diameter of 6.5 mm and a thickness of 3 mm were placed in the disks at 90-degree intervals between groups. The manufactured devices generated a clear signal sequence from all groups of magnets, allowing the control unit to determine the direction and speed of shaft rotation at any given time.

Claims

1. A device for determining the direction of rotation of a shaft, comprising a Hall sensor and a control unit for processing signals received from the Hall sensor, characterized in that the device comprises a disk secured on the shaft, blind holes are made on the end surface of the disk, in which permanent magnets are installed, wherein the blind holes form three groups, where the first group contains one hole, the second group - two holes, the third group - three holes, the outer holes of each group are at an equal distance from the outer holes of adjacent groups, and the distances between the holes in the second and third groups are the same.

2. The device according to paragraph 1, characterized in that the Hall sensor is located with an air gap in relation to the installation area of ​​the permanent magnets.

3. The device according to paragraph 1, characterized in that the disk is made of a non-magnetic material.

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