Shaft system vibration measurement system and method

Abstract

The present invention discloses a shaft system vibration measurement system and a shaft system vibration measurement method. The shaft system vibration measurement system includes at least two wireless acceleration sensors, which are arranged on the outer surface of the shaft system to obtain the acceleration of the shaft system when it rotates; a collection device, which is connected to the signals of multiple wireless acceleration sensors and is used to obtain the signals sent by the wireless acceleration sensors; a processing device, which is connected to the collection device and is used to calculate the vibration of the shaft system according to the signals sent by the collection device. Since a wireless acceleration sensor that does not require wire connection is used, the device is not limited by the installation position of the gear disc, and can simultaneously complete the multi-point torsional vibration and lateral vibration measurement of the diesel engine shaft system.

Description

Technical Field

[0001] The invention relates to the field of shaft vibration measurement for marine diesel engines, and in particular to a shaft vibration measurement system and method. Background Art

[0002] Shaft system vibration includes torsional vibration and lateral vibration. Commonly used marine diesel engine shaft system torsional vibration measurement devices are divided into contact type and non-contact type. Among them, non-contact measurement devices include combined type (toothed disc and magnetic sensor are installed as one piece), separate type (toothed disc and magnetic sensor are installed separately), transmission type (toothed disc and transmission sensor are installed separately), and reflection type (reflective paper tape replaces toothed disc and is installed separately from reflection sensor). Although the sensors and installation methods used are different, the torsional vibration measurement methods using such devices are based on the "tooth measurement" principle. Such devices require less preparation work for measurement, are convenient to measure, and the measurement process does not interfere with the normal operation of the shaft, so they are widely used. However, such devices have the following disadvantages: First, such devices need to be installed at a position with an equally divided tooth structure on the shaft system for measurement, which strictly limits the position of the measuring point; second, such devices require the spacing of the teeth to be strictly equally divided, and the indexing error and tooth profile error will seriously affect the measurement error; finally, the upper limit frequency of the measurement signal of such devices is low, which is suitable for measuring low-order torsional vibration signals.

[0003] The contact measurement device mainly attaches a strain sensor (such as a strain gauge) to the shaft to measure the shear strain of the shaft. The change of shear strain over time reflects the torsional vibration of the shaft system. The strain gauge has a wide frequency response range and high sensitivity, but the device cannot measure the rigid body torsional vibration of the shaft, and has high requirements for the surface roughness of the pasting part.

[0004] In the prior art, the measurement of shaft lateral vibration can also be divided into contact measurement and non-contact measurement. Among them, contact measurement generally uses a velocity sensor or an acceleration sensor to be set at a fixed position such as a bearing seat, a machine body and a foundation to measure the vibration at that location, thereby indirectly reflecting the lateral vibration of the shaft. This method is not as direct as the method of directly measuring the rotating shaft, cannot fully reflect the vibration of the rotating shaft, and is relatively inaccurate.

[0005] Non-contact measurement uses an eddy current sensor to measure the relative displacement of the shaft relative to the sensor probe. This method uses the change in the gap between the shaft surface and the end of the sensor probe to receive vibration and measure the vibration displacement of the shaft center. However, this method is only applicable to metal materials and cannot be used to measure non-metallic shaft systems. The area of ​​the measuring point position is required to be 3 times the area of ​​the sensor probe, and the measurement result is affected by the processing accuracy of the roundness and surface roughness at the measuring point position. Summary of the invention

[0006] A series of simplified concepts are introduced in the Summary of the Invention, which will be further described in detail in the Detailed Description of the Invention. The Summary of the Invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0007] In order to at least partially solve the above problems, the present invention provides a shaft system vibration measurement system and method. The shaft system vibration measurement system comprises:

[0008] At least two wireless acceleration sensors, arranged on the outer surface of the shaft system, for obtaining the acceleration of the shaft system when it rotates;

[0009] A collection device, connected to the plurality of wireless acceleration sensor signals, and used to obtain the signals sent by the wireless acceleration sensors;

[0010] A processing device is connected to the acquisition device and is used to calculate the vibration of the shaft system based on the received signal sent by the acquisition device.

[0011] The shaft vibration measurement system provided by the present invention adopts a wireless acceleration sensor that does not require wire connection, so that the device is not limited by the installation position of the gear plate, and can simultaneously complete the multi-point torsional vibration and lateral vibration measurement of the diesel engine shaft system. In particular, it can realize the operation safety analysis of components such as torsional vibration dampers and high elastic couplings through actual measured values, instead of obtaining safety evaluation results by estimation in the past.

[0012] In an embodiment, an angle formed between adjacent wireless acceleration sensors and the center of the axis system is greater than or equal to 90 degrees.

[0013] In this way, the acceleration values ​​at multiple points can be measured.

[0014] In an embodiment, there are two wireless acceleration sensors, and the angle formed between the two wireless acceleration sensors and the center of the shaft system is 180 degrees, so as to measure torsional vibration.

[0015] Thus, torsional vibration can be measured using only two wireless accelerometers.

[0016] In an embodiment, there are three wireless acceleration sensors, wherein the angle formed between two of the wireless acceleration sensors and the center of the axis system is 180 degrees, and the other one is located in the middle of the two wireless acceleration sensors to measure the positions of torsional vibration and lateral vibration.

[0017] In an embodiment, there are four wireless acceleration sensors, and the angle formed between adjacent wireless acceleration sensors and the center of the shaft system is equal to 90 degrees, so as to measure the positions of torsional vibration and lateral vibration.

[0018] This allows simultaneous measurement of torsional vibration and lateral vibration.

[0019] In an embodiment, the plurality of wireless acceleration sensors are arranged on the same plane.

[0020] In an embodiment, the acquisition device includes a signal preconditioning unit and a synchronous acquisition unit, the signal preconditioning unit is used to amplify and anti-alias filter the analog signal measured by the wireless acceleration sensor, and the synchronous acquisition unit is used to convert the analog signal after amplification and anti-alias filtering into a digital signal.

[0021] The present invention also provides a method for measuring shaft system vibration, the method comprising:

[0022] Get the acceleration value of each measuring point;

[0023] The torsional vibration value and the lateral vibration value are determined according to the acquired acceleration value of each measuring point.

[0024] Therefore, the device is not limited by the installation position of the gear disc, and the wireless acceleration sensor can be used to complete the multi-point torsional vibration and lateral vibration measurement of the diesel engine shaft system.

[0025] In an embodiment, determining the torsional vibration value according to the acquired acceleration value of each measuring point includes:

[0026] Determine the torsional vibration acceleration of each measuring point according to the acceleration value of each measuring point;

[0027] Determine the torsional vibration angular acceleration value according to the torsional vibration acceleration;

[0028] A torsional vibration value is determined according to the torsional vibration angular acceleration value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The following drawings of the present invention are used as part of the present invention for understanding the present invention. The drawings show embodiments of the present invention and their descriptions to explain the principles of the present invention. In the drawings,

[0030] Figure 1 This is the measurement point layout diagram of the shaft vibration measurement system;

[0031] Figure 2 It is the connection diagram of each device in the shaft vibration measurement system;

[0032] Figure 3A schematic diagram of a wireless acceleration sensor being arranged on the surface of a shaft system;

[0033] Figure 4a It is a schematic diagram of the arrangement of two wireless acceleration sensors;

[0034] Figure 4b The figure is a schematic diagram of the arrangement of three wireless acceleration sensors;

[0035] Figure 4c The figure is a schematic diagram of the arrangement of four wireless acceleration sensors;

[0036] Figure 5 The figure is a flow chart of the shaft vibration measurement method. DETAILED DESCRIPTION

[0037] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0038] Figure 2 A shaft vibration measurement system is provided in an embodiment of the present invention. The shaft vibration measurement system can be used to measure the torsional vibration and lateral vibration of the shaft. The device may include a plurality of wireless acceleration sensors 20, a collection device 30 and a processing device 40. Specifically, the wireless acceleration sensor 20 may be used to detect the acceleration of an object when it moves. The wireless acceleration sensor 20 may include a plurality of wireless acceleration sensors. Figure 1 and Figure 3 As shown, a plurality of wireless acceleration sensors 20 can be respectively arranged on the outer surface of the shaft system 10. When the shaft system 10 rotates, the wireless acceleration sensor 20 can detect the magnitude of the acceleration of the shaft system 10 during rotation, and then determine the torsional vibration and lateral vibration values ​​of the shaft system 10 according to the magnitude of the acceleration.

[0039] The number of acceleration sensor assemblies can be various, and the installation positions of different numbers are also different accordingly. For example, there are at least two wireless acceleration sensors 20, and when they are arranged outside the shaft system 10, the angle formed between adjacent wireless acceleration sensors 20 and the center of the shaft system 10 is greater than or equal to 90 degrees. More specifically, when only torsional vibration needs to be measured, refer to Figure 4a As shown, there may be two wireless acceleration sensors 20. The angle formed between the two wireless acceleration sensors 20 and the center of the shaft system 10 is 180 degrees, or refer to Figure 4bAs shown, there may be three wireless acceleration sensors 20, wherein the angle formed between two wireless acceleration sensors 20 and the center of the shaft system 10 is 180 degrees, and the other one is located in the middle of the two wireless acceleration sensors 20. When it is necessary to measure torsional vibration and lateral vibration, refer to Figure 4c As shown, there may be four wireless acceleration sensors 20, and the angle formed between adjacent wireless acceleration sensors 20 and the center of the shaft system 10 is equal to 90 degrees. Different numbers of wireless acceleration sensors 20 can be arranged on a plane perpendicular to the center line of the shaft system, thereby ensuring that the acceleration values ​​detected by each wireless acceleration sensor 20 are on the same plane.

[0040] For example, a marine diesel engine test bench is composed of a torsional vibration damper - a diesel engine - a high elastic coupling - a dynamometer. In order to measure the operating safety of the shaft system 10 components, the shaft system 10 is a common combination of the transmission shafts in the marine diesel engine test bench. Two groups of measuring points, each consisting of two wireless acceleration sensors 20, are arranged on the inner and outer rings of the torsional vibration damper 11. Two groups of measuring points, each consisting of four wireless acceleration sensors 20, are arranged on the active end 12 and the driven end 13 of the high elastic coupling. Figure 1 As shown, measuring point No. 1 is arranged at the inner ring of the torsional vibration damper 11, including two wireless acceleration sensors 20 (1#); measuring point No. 2 is arranged at the outer ring of the torsional vibration damper 11, including two wireless acceleration sensors 20 (2#); measuring point No. 3 is arranged at the active end 12 of the high elastic coupling, including four wireless acceleration sensors 20 (3#); measuring point No. 4 is arranged at the driven end 13 of the high elastic coupling, including four wireless acceleration sensors 20 (4#).

[0041] The acquisition device 30 is connected to the plurality of wireless acceleration sensors 20 by signals, and is used to obtain the analog signal emitted by the wireless acceleration sensor 20. The signal connection method may include multiple methods, such as wireless connection, infrared signal connection or communication connection, etc. As long as the acceleration sensor can realize wireless connection with the acquisition device 30, it meets the requirements of the present application, and can solve the problem in the prior art that it cannot be set on the surface of the moving shaft system due to the use of wired connection. When the shaft system 10 rotates, the wireless acceleration sensor component sends the detected acceleration value of a certain position of the shaft system 10 to the acquisition device 30 in the form of an analog signal. Specifically, the acquisition device 30 may include a signal preconditioning unit and a synchronous acquisition unit. The signal preconditioning unit may be used to amplify and anti-alias filter the analog signal measured by the wireless acceleration sensor 20. The synchronous acquisition unit may be used to convert the analog signal after amplification and anti-alias filtering into a digital signal.

[0042] The processing device 40 is connected to the acquisition device 30 and is used to calculate the vibration of the shaft system 10 according to the digital signal received from the acquisition device 30. The processing device 40 has the function of storing and analyzing data. It can store the collected signals in a certain format, read, analyze and manage the measurement signals, and has data processing functions such as integral transformation, spectrum analysis, cepstrum analysis, correlation analysis, axis trajectory analysis, dynamic balance analysis, etc.

[0043] In order to make the technical personnel better understand the present invention, refer to Figure 5 The device and the measuring method of the present invention are described below with reference to specific embodiments. The measuring method generally includes the following steps; S10: obtaining the acceleration value of each measuring point; S20: determining the torsional vibration value and the lateral vibration value according to the obtained acceleration value of each measuring point. Specifically, for the torsional vibration damper, during the operation of the shaft system 10, it is mainly a rigid body vibration, so only the torsional vibration of the inner ring and the outer ring needs to be measured, and the relative torsional angle of the inner ring and the outer ring is obtained by comparison, which is used to measure the operating safety of the torsional vibration damper. Refer to Figure 1 As shown in the figure, there are two wireless acceleration sensors 20 at the measuring point No. 1 (1#). Figure 4a The two sensors are arranged at 180° relative to each other, and the measured acceleration signals include torsional and lateral vibration. From the sensor sensitivity arrangement direction, it can be seen that the torsional acceleration signals obtained by the two sensors are the same, while the lateral vibration acceleration signals have opposite phases, as shown in formula (1). The signal a is measured by the two sensors at measuring point 1. (1-1) 、a (1-2) By comparing the torsional vibration acceleration a of the inner ring of the torsional vibration damper, we can get 1t .

[0044]

[0045] Where: a (1-1) The signal measured by the first sensor at measuring point 1; a (1-2) The signal measured by the second sensor at measuring point 1; a 1t is the torsional vibration acceleration at measuring point 1; a 1ω is the lateral vibration acceleration at measuring point 1; α1 is the angle between the lateral vibration direction and the sensor sensitivity direction.

[0046] The angular acceleration ω1′ is calculated according to formula (2). ω1′ is the rate of change of the angular velocity of the shaft at measuring point 1.

[0047] ω1′=a1t / r1 (2)

[0048] Where: ω1′ is the torsional vibration angular acceleration at measuring point 1; r1 is the radius of gyration at measuring point 1.

[0049] By integrating ω1′ twice, we can get the angular displacement θ1 of the inner ring of the torsional vibration damper, as shown in equation (3). Then, we use data processing methods such as order analysis and spectrum analysis to analyze the torsional vibration response at this location.

[0050] θ1=∫∫ω1′ (3)

[0051] Where: θ1 is the angular displacement at measuring point 1.

[0052] Similarly, the torsional vibration angular acceleration ω2′ of the outer ring of the torsional vibration damper can be obtained.

[0053] By integrating ω2′ twice, we can get the angular displacement θ2 of the outer ring of the torsional vibration damper.

[0054] The difference between the torsional vibration angles of the inner and outer rings of the torsional vibration damper is the relative torsional angle of the torsional vibration of the torsional vibration damper, see formula (4).

[0055] Δθ 1，2 =θ2-θ1 (4)

[0056] Δθ 1，2 That is the torsional vibration value, which is an indicator used to measure the operating safety of the torsional vibration damper.

[0057] For a high elastic coupling, during the operation of the shaft system 10, it is necessary to measure not only the torsional vibration but also the lateral vibration. Therefore, four wireless acceleration sensors 20 are arranged as a group of measuring points to obtain the torsional vibration and lateral vibration of the active end and the driven end respectively. Figure 4c The four sensors are arranged at 90°. The measured acceleration signals include torsion and lateral vibration. From the sensor sensitivity arrangement direction, it can be seen that the torsion acceleration signals obtained by the four sensors are the same, while the lateral vibration acceleration signals have a phase difference of 90°, as shown in formula (5). The signal a is measured by the four sensors at measuring point 3. (3-1) 、a (3-2) 、a (3-3) 、a (3-4) By comparing the two of them, we can get the torsional vibration acceleration a of the inner ring of the torsional vibration damper. 3t and lateral vibration acceleration a 3w .

[0058]

[0059] Here, the torsional vibration acceleration a 3tThe processing method is the same as the torsional vibration acceleration signal processing method of the torsional vibration damper. Finally, the torsional vibration angular acceleration ω3′ and ω4′ of the master and slave ends of the high elastic coupling are obtained, and the angular velocity change rate of the master and slave ends of the high elastic coupling is analyzed; the torsional vibration angular displacements θ3 and θ4 at the two places are obtained, and the torsional vibration response of the master and slave ends of the high elastic coupling is analyzed by data processing methods such as order analysis and spectrum analysis; the torsional vibration angular displacement difference Δθ is obtained 3，4 , that is, the torsional vibration value, is used to measure the torsional vibration operation safety of the high elastic coupling.

[0060] Transverse vibration acceleration a of the driving and driven ends of the high elastic coupling 3w0 、a 3w90 、a 4w0 、a 4w90 , which is the radial amplitude of the driving and driven ends of the high elastic coupling.

[0061] The overall lateral vibration response of the high elastic coupling can be calculated as follows:

[0062]

[0063] According to a hc By comparing the required value of lateral vibration of the high elastic coupling, the safety of lateral vibration operation of the high elastic coupling can be judged.

[0064] The a measured here 3w0 、a 3w90 、a 4w0 、a 4w90 The lateral vibration analysis can also be carried out according to the conventional lateral vibration measurement and analysis method, using data processing methods such as spectrum analysis, cepstrum analysis, correlation analysis, axis trajectory analysis, dynamic balance analysis, etc.

[0065] From the above content, it can be seen that the shaft vibration measurement system provided by the present invention adopts a wireless acceleration sensor 20 that does not require wire connection, so that the device is not limited by the installation position of the gear plate, can be directly installed on the outer surface of the shaft system and can simultaneously complete the multi-point torsional vibration and lateral vibration measurement of the diesel engine shaft system. In particular, it can realize the operation safety analysis of components such as torsional vibration dampers and high elastic couplings through actual measured values, instead of obtaining safety evaluation results by estimation in the past.

[0066] The present invention has been described by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of the protection claimed by the present invention. The protection scope of the present invention is defined by the attached claims and their equivalents.

[0067] For the convenience of description, the above device is described in terms of functions and is described separately in various units. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0068] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0070] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0071] In a typical configuration, a processing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0072] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0073] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.

Claims

1. A shaft vibration measurement system, characterized in that: include At least two wireless acceleration sensors are arranged on the outer surface of the shaft system to obtain the acceleration of the shaft system when the shaft system rotates, and the outer surface is a plane perpendicular to the center line of the shaft system; A collection device, connected to the plurality of wireless acceleration sensor signals, and used to obtain the signals sent by the wireless acceleration sensors; A processing device connected to the acquisition device, used to calculate the vibration of the shaft system according to the received signal sent by the acquisition device; the angle formed between the adjacent wireless acceleration sensors and the center of the shaft system is greater than or equal to 90 degrees; The shaft system includes a high elastic coupling, and the wireless acceleration sensor is respectively arranged at the active end and the driven end of the high elastic coupling to obtain the lateral vibration acceleration of the active end and the driven end respectively. , , , , The overall lateral vibration response of the highly elastic coupling is calculated as follows: ， According to the overall lateral vibration response By comparing the magnitude of the required lateral vibration value of the highly elastic coupling, the safety of the lateral vibration operation of the highly elastic coupling is determined.

2. The shaft vibration measurement system according to claim 1, characterized in that: There are four wireless acceleration sensors at the active end and the driven end respectively, and the angle formed between adjacent wireless acceleration sensors and the center of the shaft system is equal to 90 degrees, so as to measure the position of torsional vibration and lateral vibration.

3. The shaft vibration measurement system according to claim 1, characterized in that: The acquisition device includes a signal preconditioning unit and a synchronous acquisition unit. The signal preconditioning unit is used to amplify and anti-alias filter the analog signal measured by the wireless acceleration sensor, and the synchronous acquisition unit is used to convert the analog signal after amplification and anti-alias filtering into a digital signal.

4. A method for measuring shaft vibration, characterized in that: include: Obtaining the acceleration value of each measuring point, wherein the wireless acceleration sensor is arranged on a plane perpendicular to the center line of the shaft system; Determine the torsional vibration value and the lateral vibration value according to the acquired acceleration value of each measuring point; the determining the torsional vibration value according to the acquired acceleration value of each measuring point includes: Determine the torsional vibration acceleration of each measuring point according to the acceleration value of each measuring point; Determine the torsional vibration angular acceleration value according to the torsional vibration acceleration; determining a torsional vibration value according to the torsional vibration angular acceleration value, The lateral vibration value is obtained by the lateral vibration acceleration of each measuring point. , , , The lateral vibration acceleration is measured from the active and passive ends of the highly elastic coupling in the shaft system. The overall lateral vibration response of the highly elastic coupling is calculated as follows: ， According to the overall lateral vibration response By comparing the magnitude of the required lateral vibration value of the highly elastic coupling, the safety of the lateral vibration operation of the highly elastic coupling is determined.

Images