CN115790504A - Method for measuring torsion angle of high-load long transmission shaft - Google Patents

Abstract

A method for measuring a torsion angle of a high-load long transmission shaft belongs to the technical field of transmission shaft rotation measurement. The invention aims at the problem that the conventional angle encoder is adopted to directly measure the torsion angle of the transmission shaft, and the measurement result precision is low. The method comprises the following steps: the two ends of the transmission shaft are respectively provided with a rotating speed sensor according to the phase angle difference of 90 degrees, and the middle section of the transmission shaft is provided with a speed measuring encoder; two speed measuring elements which are arranged at two ends of the transmission shaft according to the phase angle difference of 90 degrees are respectively measured by the two rotating speed sensors to obtain pulse signals of the corresponding speed measuring elements, and the time difference of the occurrence moments of the two pulse signals is calculated; measuring the rotating speed of the transmission shaft in the time difference by using a speed measuring encoder; and converting the rotating speed of the transmission shaft into an angular speed, and calculating by combining the time difference to obtain the torsion angle of the transmission shaft. The invention is used for measuring the torsion angle of the long transmission shaft.

Description

Method for measuring torsion angle of high-load long transmission shaft

Technical Field

The invention relates to a method for measuring a torsion angle of a high-load long transmission shaft, and belongs to the technical field of transmission shaft rotation measurement.

Background

The low-pressure rotor transmission shaft of a turbofan engine or the low-pressure rotor shaft of a ship gas turbine with a large bypass ratio has the advantages that the torque moment born by the rotor is increased at a high rotating speed, and the shaft system is easy to generate elastic vibration or plastic deformation due to external disturbance. The torsional vibration is a typical vibration form of a shafting-rotor system with low-pressure rotors, large span and large length-diameter ratio, and the reliability and safety of the rotor system, an engine, even an airplane or a ship are directly influenced by the torsional vibration and the torsional angle.

At present, the measurement of the torsion angle is usually realized by adopting a high-precision vibration analysis system or directly measured by adopting a traditional angle encoder, and the existing measurement method has the problems of high cost, poor compatibility with other test systems or low measurement precision.

Disclosure of Invention

The invention provides a high-load long-transmission-shaft torsion angle measuring method, aiming at the problem that the conventional angle encoder is adopted to directly measure the torsion angle of a transmission shaft and the measuring result is low in precision.

The invention relates to a method for measuring a torsion angle of a high-load long transmission shaft, which comprises the following steps,

the two ends of the transmission shaft are respectively provided with a rotating speed sensor according to the phase angle difference of 90 degrees, and the middle section of the transmission shaft is provided with a speed measuring encoder;

two speed measuring elements are arranged at two ends of the transmission shaft according to the phase angle difference of 90 degrees, two rotating speed sensors respectively measure and obtain pulse signals of the corresponding speed measuring elements, and the time difference of the occurrence moments of the two pulse signals is calculated;

measuring the rotating speed of the transmission shaft in the time difference by using a speed measuring encoder;

and converting the rotating speed of the transmission shaft into an angular speed, and calculating by combining the time difference to obtain the torsion angle of the transmission shaft.

According to the method for measuring the torsion angle of the high-load long-transmission shaft, the torsion angle is calculated by the following steps:

and subtracting 90 degrees from the product of the angular velocity and the time difference to obtain the torsion angle of the transmission shaft.

According to the method for measuring the torsion angle of the high-load long transmission shaft, the PLC data acquisition control module is adopted to acquire the pulse signal of the rotating speed sensor and the rotating speed of the transmission shaft measured by the speed measurement encoder.

According to the method for measuring the torsion angle of the high-load long transmission shaft, the PLC data acquisition control module comprises a Beifu C6930 data acquisition controller and a Beifu EL1252 data acquisition module;

the Beifu EL1252 data acquisition module acquires pulse signals of a rotating speed sensor and records a timestamp corresponding to each pulse; calculating to obtain a time difference from the two timestamps; the double-Fox C6930 data acquisition controller acquires the rotating speed of the transmission shaft measured by the speed measurement encoder.

The invention has the beneficial effects that: according to the method, after the pulse signals are measured by the rotating speed sensors, the pulse signals are converted into corresponding time signals, so that the torsion angle of the transmission shaft is calculated according to the time difference of the signals obtained by the two rotating speed sensors, and compared with a method for directly measuring the torsion angle, the method is more accurate in result and higher in precision.

The method has the advantages of simple implementation, high reliability, good compatibility, wide application range and the like, is easy to integrate into products or test beds, and is suitable for measuring the static or dynamic torsion angle of the long transmission shaft.

Drawings

FIG. 1 is a schematic block diagram of a high load long drive shaft torsion angle measurement method according to the present invention;

FIG. 2 is a schematic view of a high-load long transmission shaft provided with a speed sensor and a speed measuring encoder; in the figure, 1 is a rotating speed sensor, and 2 is a speed measuring encoder;

fig. 3 is a detailed flow chart of a method of implementing the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

First embodiment, referring to fig. 1 and 2, the present invention provides a method for measuring a torsion angle of a high-load long transmission shaft, including,

the two ends of the transmission shaft are respectively provided with a rotating speed sensor according to the phase angle difference of 90 degrees, and the middle section of the transmission shaft is provided with a speed measuring encoder;

two speed measuring elements are arranged at two ends of the transmission shaft according to the phase angle difference of 90 degrees, two rotating speed sensors respectively measure and obtain pulse signals of the corresponding speed measuring elements, and the time difference of the occurrence moments of the two pulse signals is calculated;

measuring the rotating speed of the transmission shaft in the time difference by adopting a high-precision speed measuring encoder;

and converting the rotating speed of the transmission shaft into angular speed, and calculating by combining time difference to obtain the torsion angle of the transmission shaft.

In the present embodiment, the two rotation speed sensors are arranged vertically. If two speed sensors are arranged on the same straight line of the transmission shaft, the measurement accuracy of the torsion angle is affected because the time interval for receiving the pulse signal is extremely small.

Further, the calculation method of the torsion angle is as follows:

and subtracting 90 degrees from the product of the angular velocity and the time difference to obtain the torsion angle of the transmission shaft.

And furthermore, acquiring a pulse signal of a rotating speed sensor and the rotating speed of the transmission shaft measured by a speed measuring encoder by using a PLC data acquisition control module. The PLC data acquisition control module is applied, so that the embodiment can be independently applied and can also be integrated in other data acquisition control systems.

The PLC data acquisition control module comprises a Beifu C6930 data acquisition controller and a Beifu EL1252 data acquisition module;

the Dufu EL1252 data acquisition module acquires pulse signals of the rotating speed sensor and generates a timestamp (namely pulse sampling time) corresponding to the rising edge of each pulse; calculating to obtain a time difference from the two timestamps; the double-Fox C6930 data acquisition controller acquires the rotating speed of the transmission shaft measured by the speed measurement encoder. The double-fortune C6930 data acquisition controller can calculate the real-time rotating speed of the current transmission shaft according to the acquired rotating speed signal.

The specific embodiment is as follows:

with reference to fig. 3, after the sampling system is powered on, the execution process of the software system is as follows:

1. a system self-checking sub-program: the device is used for detecting whether each field sensing signal is normal or not;

2. a rotation speed measurement subroutine; the device is used for acquiring a rotating speed signal of a field speed measuring encoder and calculating the rotating speed of a transmission shaft;

3. angular velocity calculation subroutine: the device is used for calculating the rotating speed of the transmission shaft according to the time and the distance and further calculating the angular speed of the current rotating shaft;

4. and a signal acquisition program of the rotating speed sensor: the system is used for acquiring pulse signals of rotation speed sensors on two sides of a shaft and timestamps of pulse rising edges, the cycle time of the subprogram can be set to be 50 microseconds, the time precision of EL1252 is 1 nanosecond, and the precision of a distributed clock is 1 microsecond;

5. torsion angle calculation subroutine: and calculating the torsion angle of the transmission shaft by calculating the time difference of the two pulses and combining the angular speed obtained by calculating the current rotating speed.

The method of the invention can measure the torsion angle of the rotating shaft and can also measure the torsion angle of the transmission shaft under the condition of static high load. The torsion angle measuring device can be applied to a field or tester applying a high-load long transmission shaft such as an aircraft engine or a ship and the like, and can be used for measuring the torsion angle of the field long transmission shaft.

When the method is used for measurement, the transmission shaft can be in a static loading state or a rotating state; after the PLC is electrified, the test system can start to automatically measure and calculate.

The method can meet different measurement requirements according to different arrangement positions and different speed measurement tooth numbers of the rotating speed sensors, and solves various defects and short plates existing in the traditional measurement method; meanwhile, the method of the invention can be properly modified to measure the angle of the similar phase.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.

Claims (4)

1. A method for measuring the torsion angle of a high-load long transmission shaft is characterized by comprising the following steps of,

the two ends of the transmission shaft are respectively provided with a rotating speed sensor according to the phase angle difference of 90 degrees, and the middle section of the transmission shaft is provided with a speed measuring encoder;

two speed measuring elements which are arranged at two ends of the transmission shaft according to the phase angle difference of 90 degrees are respectively measured by the two rotating speed sensors to obtain pulse signals of the corresponding speed measuring elements, and the time difference of the occurrence moments of the two pulse signals is calculated;

measuring the rotating speed of the transmission shaft in the time difference by using a speed measuring encoder;

and converting the rotating speed of the transmission shaft into angular speed, and calculating by combining time difference to obtain the torsion angle of the transmission shaft.

2. The high-load long drive shaft torsion angle measurement method according to claim 1,

the calculation method of the torsion angle comprises the following steps:

and subtracting 90 degrees from the product of the angular velocity and the time difference to obtain the torsion angle of the transmission shaft.

3. The high-load long drive shaft torsion angle measurement method according to claim 2,

and a PLC data acquisition control module is adopted to acquire pulse signals of the rotating speed sensor and the rotating speed of the transmission shaft measured by the speed measuring encoder.

4. The high-load long drive shaft torsion angle measurement method according to claim 3,

the PLC data acquisition control module comprises a Beifu C6930 data acquisition controller and a Beifu EL1252 data acquisition module;

the Beifu EL1252 data acquisition module acquires pulse signals of a rotating speed sensor and records a timestamp corresponding to each pulse; calculating to obtain a time difference from the two timestamps; the double-Fox C6930 data acquisition controller acquires the rotating speed of the transmission shaft measured by the speed measurement encoder.

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