WO2021262122A1

WO2021262122A1 - A method and an instrument for measuring speed of rotary shaft

Info

Publication number: WO2021262122A1
Application number: PCT/TR2021/050645
Authority: WO
Inventors: Serhan Özdemi̇r; Oğuzhan DOĞAN
Original assignee: İzmi̇r Yüksek Teknoloji̇ Ensti̇tüsü Rektörlüğü
Priority date: 2020-06-24
Filing date: 2021-06-23
Publication date: 2021-12-30
Also published as: TR202009847A1

Abstract

The invention is a revolution measurement of rotary shaft provided by an inductive power transmission system, which does not need to use any sensors and cable connections located on the rotating shaft, by using the lowest and highest values of the magnetic field and voltage amplitudes to measure the number of revolutions (rotation) of the rotating shafts used in the industry.

Description

A METHOD AND AN INSTRUMENT FOR MEASURING SPEED OF ROTARY

SHAFT

Technological Field:

The State of Art:

The rotary shafts are the elements that are frequently used in the industry in the known art. The rotational speed of the rotary shafts is an important parameter in the machines, devices and systems in which they are used, and must be measured and controlled. The invention, which is the subject of the description, describes a method and apparatus for measuring rotational shafts.

In the prior art, in rotary shaft speed measurement systems, the use of sensors placed on the rotary shaft is encountered. In other methods, the measurement is provided by the additional apparatus placed on the rotating shaft. The general disadvantage of these methods is that the sensors and apparatus placed on the rotating shaft cause a lot of cable on the rotating shaft and the sensors require additional power.

The disadvantages of the methods used in the prior art are listed below. - The sensor system is located on the rotating shaft and requires wiring as it is necessary to energize the sensor.

- Stabilization of sensors changes over time. - The cables on the rotating shaft deform over time, and reliable data cannot be obtained from the sensor.

- The sensor on the rotating shaft does not give reliable results over time and the constant replacement of the sensor leads to costs.

A device that can be used to measure the RPM value of axial loads and rotary shafts is mentioned in the Russian patent document with the number RU2354941 (C1) encountered in the literature search. It is claimed that higher reliability, measurement accuracy and ease of use are provided with the entioned device. In the Russian patent document, a measurement method provided with primary and secondary coils could not be revealed, as a disadvantage, reference elements were placed on the rotating shaft.

In the Korean patent document KR2007074688 (A), encountered in the literature search, a system is mentioned to measure the torque value of a rotary shaft and the number of revolutions per minute. The system and device includes a device for measuring, first and second magnets, first and second magnetic resistance sensors, and a circuit board. In the Korean patent document, sensor elements located on the shaft were found.

In the Japanese patent document numbered JPH06207972 (A) encountered in the literature search, a system is mentioned to measure whether there is material loss in a sample called core. In the mentioned document, the method provided with primary and secondary coils was not found.

In the other literature search, the device used to measure revolutions in the patent document numbered US3952220A, a method that provides speed measurement using the magnetic converter in the patent document numbered US 4306462A, a method that provides revolution measurement using the output signals of the converter in the patent document numbered US 4535288A, in the document numbered US 5311123A the sensors placed on the shaft and it is mentioned about a method that provides measurement using the signals produced by the sensors. In these patents that were investigated, in general, it was aimed to measure speed and torque, and different techniques were tried on these measurements. In the techniques used so far, the use of sensors is primarily involved. As a result, there is a need for a rotary shaft speed measurement method in which the known state of the art is overcome and it’s disadvantages are eliminated.

Brief Description of the Invention

The invention is a rotary shaft speed measurement method, in which the known state of the art is overcome, it’s disadvantages are eliminated and it has additional features. The aim of the invention is to introduce a new rotary shaft measurement method that does not contain any sensors, cables and additional equipment on the rotary shaft.

Another aim of the invention is to present the speed measurement method and device provided by the inductive power transmission system in rotary shaft speed measurement.

The another aim of the invention is to introduce a new rotary shaft speed measurement method and device that does not require any sensor-based maintenance costs and processes.

In order to realize all the objectives mentioned above and which will emerge from the detailed explanation below, the present invention is to use the lowest and highest values of the magnetic field and voltage amplitudes to measure the number of revolutions (rotation) of the rotary shafts used in the industry. It is a speed measurement device that does not need to use any sensor and cable connection and provides a speed measurement method by an inductive power transmission system it’s feature is; comprising at least one primary rectangular coil to generate a magnetic field from any machine, device or element and inducing voltage to the secondary rectangular coil, comprising at least one secondary rectangular coil induced by the primary rectangular coil attached to the rotary shaft lower surface, measuring the voltage amplitude peaks between the secondary rectangular coil and the primary rectangular coil, caused by the rotation of the secondary rectangular coil together with the rotating shaft, determining the rotation period by measuring the time to reach the peaks of the voltage amplitudes, after the rotation period is determined, It is characterized by the fact that it contains at least one microcontroller that calculates the rotational shaft speed with the formulas f=1/T and N=60*f.

Explanation of Figures:

The invention will be described with reference to the accompanying drawings so that the features of the invention will be more clearly understood. However, it is not intended to limit the invention to these particular embodiments. On the contrary, it is also intended to cover all alternatives, modifications and equivalents that may be included within the scope of the invention as defined by the appended claims. It is to be understood that the details shown are for illustrative purposes only and are intended to provide the most useful and easy- to-understand description of both the embodiment of the methods and the conventions and conceptual features of the invention. In these drawings;

Figure - 1 This is a representative view for a prior art circular inductive power transmission system.

Figure - 2 The subject of the invention is the view of the device for measuring the rotary shaft speed in the position where the induced voltage is maximum.

Figure - 3 The subject of the invention is the view of the device for measuring the rotary shaft speed in the position where the induced voltage is minimum. Figures that will help to understand this invention are numbered as indicated in the attached figure and are given below with their names.

Explanation of References:

1. Rotary shaft

2. Primary circular coil 3. Secondary circular coil

4. Mounting plate

5. Microcontroller

6. Cable

7. Primary rectangular coil 8. Secondary rectangular coil

Description of the Invention:

In this detailed description, the rotary shaft (1) speed measurement method and device, which is the subject of the invention, is explained only with examples, that will not create any limiting effect, for a better understanding of the subject. In the specification, the speed measurement method and device provided by the inductive power transmission system, which uses the lowest and highest values of the magnetic field and voltage amplitudes to measure the number of revolutions (rotation) of the rotating shafts (1) used in the industry and does not require any sensors and cable connections located on the rotating shaft (1), are described.

Figure 1 shows a view of the inductive power transmission system of the prior art. In fact, the starting point of the invention is this system. Therefore, it is necessary to have a good understanding of how this system works. Inductive power transmission systems consist of a primary circular coil (2), a secondary circular coil (3) oscillator circuit (input) and a receiver circuit. In these systems, the primary circular coil (2) acts as a transmitter and the secondary circular coil (3) acts as a receiver. The secondary circular coil (3) is connected to the rotary shaft (1) by a mounting plate (4). On the basis of inductive power transmission, the Faraday principle is valid, and in accordance with this principle, if any flux change occurs in a conductor per unit time, voltage is induced on the receiving side. When the induction occurs between the coils, the rotating shaft (1) rotates.

In order to provide the power transmission to be uninterrupted, both the secondary coil and the primary coil must be wounded in a circle shape. In this way, the magnetic field created by the primary coil will almost completely cut the conductors of the secondary coil and induce a voltage. The voltage amplitude induced from the primary circular coil (2) to the secondary circular coil (3) has a constant value since the coils (2,3) are in the form of a circle. But when the geometric shapes of the primary and secondary coils are changed, the voltage amplitude induced from the primary coil to the secondary coil changes from peak to peak. Therefore, in the invention, which is the subject of the description,ectangular coils (7,8) were used instead of circular coils (2,3), and the number of revolutions of the rotating shaft (1) was measured by determining the time intervals when the induced voltage value between the rectangular coils (7,8) was minimum and maximum This is the brief summary of the invention. In addition, during the presentation of the invention, although it was inspired by the inductive power transmission system, the invention that is the subject of the description is used only for the purpose of determining the revolution of the rotating shafts (1 ).

In figures 2 and 3, there are views of the device for measuring the rotational shaft (1), which is the subject of the invention. Accordingly, a mounting plate (4) and a secondary rectangular coil (3) are attached to the cross section of the rotating shaft (1). The secondary rectangular coil (8) is induced by a primary rectangular coil (7) . In this case, the rotary shaft (1) is in rotation. As the rotating shaft (1) rotates, the secondary rectangular coil (8) rotates with it, and the two rectangular coils (7,8) first pull the magnetic coupling field to a maximum and then to a minimum at every 90 degree rotation. In Figure 2, the short and long sides of the primary rectangular coil (7) and the secondary rectangular coil (8) match with each other. In this position, the magnetic coupling area between the rectangular coils (7,8) is at it’s maximum value. In Figure 3, the short and long sides of the primary rectangular coil (7) and the secondary rectangular coil (8) are inversely matched with each other. In this case, the magnetic coupling area between the rectangular coils (7,8) is at it’s minimum value. In other words, for every 90 degree turn of the two rectangular coils (7,8), the magnetic coupling field becomes a maximum and then a minimum. When the time elapsed between the primary rectangular coil (7) and the secondary rectangular coil (8) at which the magnetic voltage amplitude value is maximum is calculated, the number of revolutions of the rotating shaft (1) can be calculated. In order to achieve this, a microcontroller (5) is used, which is integrated with a cable (6) in the speed measuring device. The microcontroller (5) measures the voltage amplitude values with the voltage meter inside. The stopwatch works by means of the timer located in the microcontroller (5). This stopwatch is started when its first maximum value is seen and stopped at the second maximum value after two minimum values. The elapsed time is the rotation period of the rotating shaft. After this measurement; f=1/T according to the above formula, it is written in the form of the following equation,

N=60*f revolution of rotary shaft is calculated in accordance with this formula.

With the invention, which is the subject of the description, two coils and voltage amplitudes caused by the changes of magnetic field between them, without the need for a sensor or apparatus integrated into the rotating shaft (1), are provided to measure the rotational shaft (1) revolution.

Claims

1 The invention is an inductive method that does not need to use any sensors and cable connections located on the rotating shaft (1) by using the lowest and highest values of the magnetic field and voltage amplitudes to measure the number of revolutions (rotation) of the rotating shafts (1) used in the industry. It is a revolution measurement device that provides the revolution measurement method provided by the inductive power transmission system, and it^'s feature is ;

❖ comprising at least one primary rectangular coil (7) to generate a magnetic field from any machine, device or element and induce voltage to the secondary rectangular coil (8), comprising at least one secondary rectangular coil (8) induced by the primary rectangular coil (7) attached to the lower surface of the rotating shaft (1),

- measuring the voltage amplitude peaks between the secondary rectangular coil (8) and the primary rectangular coil (7), caused by the rotation of the secondary rectangular coil (8) together with the rotating shaft (1),

- detecting the rotation period by measuring the time for the voltage amplitudes to reach their peaks,

- calculating the rotational shaft (1 ) revolution with the formulas f=1 / T and N=60*f after the rotation period is determined, is characterized by containing at least one microcontroller (5).

2 It is a speed measurement device in accordance with claim 1 , and its feature is; It contains at least one stopwatch inside the microcontroller (5) to measure the time for the voltage amplitudes to reach their peaks.

3 It is a speed measurement device in accordance with claim 1 , and its feature is; It contains at least one current meter and/or voltage meter and/or sensor within the microcontroller (5) to detect the voltage amplitudes between the secondary rectangular coil (8) and the primary rectangular coil (7).

4 It is a speed measurement device in accordance with claim 1 , and its feature is; comprises at least one mounting plate (4) that allows the secondary rectangular coil (8) to be mounted in the cross section of the rotating shaft (1 ) .

5 It is a speed measurement device in accordance with claim 1 , and its feature is; characterized by at least one cable (6) to connect the microcontroller (5) to the primary rectangular coil (7).

6 It is a speed measurement device in accordance with claim 1 , and its feature is; primary rectangular coil (7) and secondary rectangular coil (8) elements have any form except the circular form in order to obtain minimum and maximum voltage amplitudes.