CN108982900A - Axis revolving speed precision measurement system and measurement method under a kind of full revolving speed - Google Patents

Abstract

The present invention is the axis revolving speed precision measurement system under a kind of full revolving speed, measuring system includes measuring device, hub, device main shaft, shaft coupling, signal processing module, measuring device and hub are coaxially fixed on device main shaft, hub output end connection signal processing module, device main shaft connects a rotation axis by shaft coupling, driving device main shaft and the measuring device being fixed on device main shaft when rotation axis full rotational speed, hub is moved with same rotational speed, measured revolving speed is converted the output of analog quantity voltage signal by measuring device, and it is acquired by hub, collected voltage signal is converted to corresponding measurement revolving speed and shown by signal processing module.The present invention is based on centrifugal modellings and piezoelectric effect, a kind of axis revolving speed precision measurement apparatus under full revolving speed, method and system are provided, apparatus structure is simple, and method is concise, system design rationally, for full revolving speed lower rotary shaft revolving speed has good measurement performance.

Description

A shaft speed precision measurement system and measurement method at full speed

technical field

The invention belongs to the technical field of rotational speed measurement, and in particular relates to a shaft rotational speed precision measurement device system and a measurement method under full rotational speed.

Background technique

Speed is an important characteristic parameter in performance testing. The determination of many characteristic parameters of power machinery is inseparable from the functional relationship related to speed. Therefore, speed measurement is a key point in various fields of industrial production. At present, the commonly used speed measurement methods at home and abroad are: Electromagnetic type, Hall type, photoelectric type; the electromagnetic type uses the frequency of the induced current generated by cutting the magnetic field lines of the rotor in the rotating magnetic field, and its measurement results are more accurate, but it is greatly affected by electromagnetic interference; the Hall type uses the Hall switch element For measuring the speed, the measurement accuracy depends on the accuracy of the Hall element; the photoelectric method is a non-contact speed measurement method to measure the speed by measuring the frequency or period of the speed signal, but it is very easy to cause torsional vibration of the rotating shaft or Creeping, the orthogonality of the output signal of the photoelectric encoder is destroyed.

Contents of the invention

In order to solve the above problems, the present invention provides a precise shaft speed measurement system and method at full speed based on the centrifugal force effect and the piezoelectric effect. Rotating shaft speed has good measurement performance.

In order to achieve the above object, the present invention is achieved through the following technical solutions:

The present invention is a precision shaft speed measurement system at full speed. The measurement system includes a measurement device, a hub, a device main shaft, a shaft coupling, and a signal processing module. The measurement device and the hub are coaxially fixed on the device main shaft, and the output end of the hub is connected to Signal processing module, the main shaft of the device is connected to a rotating shaft through a coupling. When the rotating shaft rotates at full speed, it drives the main shaft of the device, the measuring device and the hub fixed on the main shaft of the device to move at the same speed, and the measuring device converts the measured speed into an analog quantity. The voltage signal is output and collected by the hub, and the signal processing module converts the collected voltage signal into the corresponding measured rotational speed and displays it.

The further improvement of the present invention is: the measuring device includes a device cavity, mercury, piston, transmission block, return spring, and piezoelectric crystal, and the interior of the device cavity is filled with pistons, transmission blocks, return springs, and piezoelectric crystals. Filled with mercury, the piston and the transmission block constitute the internal transmission parts of the measuring device. The cavity of the device is composed of two concentric closed circular tubes, and each closed circular tube is composed of multiple pipes connected end to end. The outer ring tube and the inner ring tube They are connected by four equiangularly distributed pipes, the piston is placed in the pipe connected between the outer ring tube and the inner ring tube, the piezoelectric crystal is placed in the outer ring tube, and the adjacent two Connect the middle part of the pipeline interface, the number of filling areas of the piezoelectric crystal is four, the return springs are placed on both sides of the piezoelectric crystal area, the number of return springs is eight, and the transmission block is placed between two adjacent return springs.

The further improvement of the present invention is: when the measuring device is in a static state, the return spring, under the action of its own elastic force, ensures that the interior of the device cavity is filled with mercury except for the piston, the transmission block, the return spring and the piezoelectric crystal area, and the mercury is in the compressed state.

A measurement method for precise measurement of shaft speed at full speed. When the piezoelectric crystal is rotating at full speed in the measuring device, the radial centrifugal force of mercury transforms the extrusion force on the piezoelectric crystal through the piston, transmission block and return spring. Under the piezoelectric effect, the corresponding voltage signal is generated and collected by the hub;

The mercury in the measuring device generates radial centrifugal force due to rotation, and the radial centrifugal force pushes the piston and acts on the transmission block to squeeze the return spring. The return spring transmits the extrusion force to the piezoelectric crystal to generate piezoelectric effect, generating A voltage signal corresponding to the extrusion force;

After the hub collects and transmits the electrical signal generated by the piezoelectric effect to the signal processing module, the signal processing module realizes the conversion of the electrical signal and the corresponding rotational speed, and completes the rotational shaft rotational speed measurement.

The beneficial effects of the present invention are: the rotating shaft at full rotational speed of the present invention rotates through the main shaft of the coupling drive device, the measuring device fixed on the main shaft of the device realizes the conversion of rotational speed and voltage signal, and the hub transmits the collected voltage signal to the signal The processing module completes the measurement of the rotation speed of the rotating shaft. The structure is simple, reasonable and novel, and the operation is convenient. It has good measurement performance for the rotation speed of the rotating shaft at full rotation speed.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

FIG. 2 is a schematic structural view of the measuring device 1 of the present invention.

Fig. 3 is a partially enlarged view of Fig. 2 of the present invention.

Among them: 1-measurement device; 2-device cavity; 3-mercury; 4-piston; 5-transmission block; 6-return spring; 7-piezoelectric crystal; 8-hub; 9-device spindle; 10-coupling device; 11-signal processing module; 12-rotation shaft.

Detailed ways

In order to deepen the understanding of the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments, which are only used to explain the present invention and do not limit the protection scope of the present invention.

As shown in Figures 1-3, the present invention is a precision shaft speed measurement system at full speed. The measurement system includes a measurement device 1, a hub 8, a device main shaft 9, a coupling 10, and a signal processing module 11. The measuring device 1 and the hub 8 are coaxially fixed on the main shaft 9 of the device, the output end of the hub 8 is connected to the signal processing module 11, and the main shaft 9 of the device is connected to a rotating shaft through the coupling 10 12. When the rotating shaft 12 rotates at full speed, it drives the main shaft 9 of the device and the measuring device 1 and the hub 8 fixed on the main shaft 9 of the device to move at the same speed, and the measuring device 1 converts the measured speed into an analog The measured voltage signal is output and collected by the hub 8. The signal processing module 11 converts the collected voltage signal into a corresponding measurement speed and displays it. The measurement device 1 includes a device cavity 2, mercury 3, and a piston 4. , transmission block 5, return spring 6, piezoelectric crystal 7, the inside of described device cavity 2 is all filled by mercury 3 except piston 4, transmission block 5, return spring 6, piezoelectric crystal 7 filling areas, and described piston 4 and the transmission block 5 constitute the internal transmission part of the measuring device 1, and the device cavity 2 is composed of two concentric airtight circular tubes, each of which is composed of a plurality of pipelines connected end to end, and the outer circle is round The tube and the inner tube are connected by four equiangularly distributed tubes, and the piston 4 is placed in the tube connected between the outer tube and the inner tube to ensure that the entire device cavity 2 is airtight. State, there will be no leakage of mercury 3, the piezoelectric crystal 7 is placed in the circular tube of the outer ring, in the middle of the interface between two adjacent connecting pipes, the number of filling areas of the piezoelectric crystal 7 is four, and the reset The spring 6 is placed on both sides of the piezoelectric crystal 7 area, the number of the return springs 6 is eight, the transmission block 5 is placed between two adjacent return springs 6, and the return spring 6 is measured When the device 1 is in a static state, under the action of its own elastic force, it is ensured that the interior of the device cavity 2 is filled with mercury 3 except for the piston 4, the transmission block 5, the return spring 6 and the piezoelectric crystal 7, and the mercury 3 is in a compressed state.

A measurement method for precise measurement of shaft rotation speed at full rotation speed using the measurement system, the measurement method includes: when the piezoelectric crystal 7 rotates at full speed in the measurement device 1, the radial centrifugal force of the mercury 3 passes through the The piston 4, the transmission block 5 and the return spring 6 convert the pressing force on the piezoelectric crystal 7, and generate a piezoelectric effect under its action to generate a corresponding voltage signal, which is collected by the hub 8; The mercury 3 in the measuring device 1 generates radial centrifugal force due to rotation, and the faster the rotating speed, the greater the centrifugal force;

Mercury is denoted as F by centrifugal force, which can be calculated by formula (1):

F=mv ² /r (1)

Among them, r is the radius of the device cavity 2; v is the rotational speed of the device; m is the mass of mercury in the device exemplified in the present invention, if filled with other materials, it can be calculated from the material density and volume parameters.

The radial centrifugal force pushes the piston 4 and acts on the transmission block 5, which produces a squeezing effect on the return spring 6, and the return spring 6 transmits the pressing force to the piezoelectric crystal 7 to generate a compression force. The electrical effect generates a voltage signal corresponding to the extrusion force; during the entire physical quantity conversion process, different rotational speeds correspond to different radial centrifugal forces, which in turn produce different degrees of piezoelectric effect, and the generated electrical signals are also different. After the hub 8 collects the electrical signal generated by the piezoelectric effect and transmits it to the signal processing module 11, the signal processing module 11 realizes the conversion between the electrical signal and the corresponding rotational speed, and completes the rotational speed measurement of the rotating shaft 12.

Claims (4)

1. the axis revolving speed precision measurement system under a kind of full revolving speed, the measuring system include measuring device (1), hub (8), Device main shaft (9), shaft coupling (10), signal processing module (11), it is characterised in that: the measuring device (1) and the line concentration Device (8) is coaxially fixed on described device main shaft (9), and hub (8) output end connects the signal processing module (11), Described device main shaft (9) connects a rotation axis (12) by the shaft coupling (10), when the full rotational speed of the rotation axis (12) Drive described device main shaft (9) and the measuring device (1) being fixed on described device main shaft (9), hub (8) with same rotational speed Movement, the measuring device (1) converts analog quantity voltage signal for measured revolving speed and exports, and is adopted by the hub (8) Collected voltage signal is converted to corresponding measurement revolving speed and shown by collection, the signal processing module (11).

2. the axis revolving speed precision measurement system under a kind of full revolving speed according to claim 1, it is characterised in that: the measurement dress Setting (1) includes device cavity (2), mercury (3), piston (4), drive block (5), reset spring (6), piezo-electric crystal (7), the dress It is internal in addition to piston (4), drive block (5), reset spring (6), piezo-electric crystal (7) filling region to set cavity (2), by mercury (3) it fills, the piston (4) and the drive block (5) constitute measuring device (1) internal transmission part, described device cavity (2) Be made of two concentric closed round tubes, each closed round tube is the end to end composition of multiple pipelines, outer ring round tube with it is interior Be connected between circle round tube by four pipelines being angularly distributed, the piston (4) be placed in outer ring round tube and inner ring round tube it Between in the pipeline that is connected, the piezo-electric crystal (7) is placed in the round tube of outer ring, in two adjacent connecting pipe interfaces Middle part, the filling region quantity of the piezo-electric crystal (7) are four, and the reset spring (6) is placed in piezo-electric crystal (7) region two Side, the quantity of the reset spring (6) are eight, the drive block (5) be placed in the reset spring (6) of adjacent two it Between.

3. the axis revolving speed precision measurement system under a kind of full revolving speed according to claim 2, it is characterised in that:

The reset spring (6) under own resilient effect, guarantees device cavity when measuring device (1) remains static (2) internal to be filled by mercury (3) in addition to piston (4), drive block (5), reset spring (6) and piezo-electric crystal (7) region, mercury (3) it is in confined state.

4. the measurement method of the axis revolving speed accurate measurement under a kind of full revolving speed according to claim 1, it is characterised in that: the survey Amount method includes:

When the measuring device (1) rotates at full speed, mercury (3) radial centrifugal force passes through described the piezo-electric crystal (7) Piston (4), the drive block (5) and the reset spring (6) convert the squeezing action power to the piezo-electric crystal (7), at it Effect is lower to generate piezoelectric effect, generates relevant voltage signal, and acquired by the hub (8)；

For the interior mercury of the measuring device (1) (3) because rotation generates radial centrifugal force, radial centrifugal force pushes the piston (4) simultaneously The drive block (5) are acted on, squeezing action are generated to the reset spring (6), the reset spring (6) is by squeezing action power Being transferred to the piezo-electric crystal (7) makes it generate piezoelectric effect, generates voltage signal corresponding with squeezing action power；

The hub (8) is by the electrical signal collection that piezoelectric effect generates and after being transmitted to signal processing module (11), at signal The conversion that module (11) realize electric signal and corresponding revolving speed is managed, rotation axis (12) tachometric survey is completed.