TWI633312B - Method and system for measuring channel precision of crossed roller bearing - Google Patents

Abstract

A method and system for measuring the channel accuracy of a crossed roller bearing, wherein the servo motor unit drives the cross roller bearing to rotate. The current input module captures the current signal of the servo motor unit on the time axis. Then, the operation control unit reads the current signal, and records the current signal as the current time domain signal; and converts the current time domain signal into the frequency domain signal by using the fast Fourier transform module, and then judges the cross roll by the characteristics of the frequency domain signal. The inspection quality information of the sub-bearings, wherein the inspection quality information is selected from the information of the channel roundness of the crossed roller bearing, the variation of the roller diameter, the channel roughness and the assembly accuracy, etc., and the servo motor The motor current is collected corresponding to the frictional resistance of the unit to obtain the inspection quality information of the crossed roller bearing.

Description

Method and system for measuring channel precision of crossed roller bearing

The invention relates to a method and a system for measuring the channel precision of a crossed roller bearing, in particular to a bearing measuring technology for obtaining the quality information of the cross roller bearing by the motor current collecting technology corresponding to the frictional resistance.

According to the conventional bearing technology, since the crossed roller bearing is a roller bearing with high rotation precision, and the circular roller is arranged in an orthogonal manner, the load in all directions can be withstood, and thus Cross-roller bearings have indeed been widely valued and favored by related industries. As for the bearing inspection, most of the bearings are contacted to contact the outer ring of the bearing for vibration detection. What is the specific test data for the bearing? Specifically, the probe of the bearing inspection equipment used by the general bearing manufacturer adopts contact contact with the outer ring of the bearing; or the vibration sensor is used to sense the vibration state of the bearing to capture the vibration signal (ie, time) Domain), and the frequency spectrum signal is changed from the time domain signal to the frequency domain signal by the spectrum analysis device and then through the fast Fourier transform (FFT) method; wherein, the vibration generated by the inner ring defect of the bearing is taken as an example, when the rolling element contacts In the case of defects, transient short pulses are generated, which are excited in different frequency bands, which can range from a few hundred Hz to several hundred kHz. These pulse signals are passed through a low-pass filter and analyzed by envelope analysis and fast Fourier transform (FFT) to see the frequency distribution of bearing defects. The above-mentioned conventional detection techniques can be analyzed by the frequency domain signal feature detection technology that has been the prior art (ie, the frequency distribution characteristics are compared with the bearing channel roundness, The detection data judgment technique of the outer diameter accuracy of the roller and the channel roughness is used to judge the quality detection data of the bearing; however, since the conventional technique uses the probe contact method to detect the vibration state of the bearing, there is a probe. The difficulty of contact operation and the waste of working hours are caused, resulting in inconvenience and troubles in detection.

In addition, general bearing manufacturers will also use the bearing inspection equipment shown below to test the quality of various bearing inspection items:

1. The inner and outer diameter of the bearing is detected by the inner and outer diameter detectors of the bearing to detect the inner and outer diameter data of the crossed roller bearing to determine whether the bearing product has an inner and outer diameter dimension error.

2. Bearing radial pressure test, through the large bearing pressure test machine to detect the radial pressure data of the crossed roller bearing to determine whether the radial pressure of the bearing product reaches the preset pressure value.

3. Bearing salt spray test, through the large bearing salt spray test machine to detect the salt spray resistance data of the cross roller bearing to determine whether the salt spray resistance of the bearing product reaches the preset standard value.

4. Bearing roundness test, through the large bearing roundness test machine to detect the roundness data of the crossed roller bearing to determine whether the roundness data of the bearing product is within the standard value.

5. Bearing clearance test, through the bearing clearance tester to detect the bearing clearance data of the crossed roller bearing to determine whether the clearance data of the bearing product is within the standard value.

6. Bearing metallographic/hardness test, through large bearing metallographic/hardness tester The metallographic/hardness data of the crossed roller bearing is measured to determine if the metallographic/hardness data of the bearing product is within the standard value.

7. Bearing life test, through the large bearing life test machine to detect the service life data of the cross roller bearing to determine whether the service life of the bearing product is within the standard value.

It is known from the above that the conventional cross-roller bearing detection technology must use the detection equipment for the purpose of detecting the project for each test item, and thus the detection data of the exclusive inspection item can be detected. Although the detection technology can detect the detection data of the exclusive inspection items; however, the cost of the inspection equipment for each exclusive inspection item is not cheap, resulting in an explosion of inspection costs, and also increases the labor of inspection and labor costs. Therefore, the conventional detection technology is indeed not perfect, and there is still a need for further improvement.

In view of the above-mentioned conventional cross roller bearing detection technology and the defects caused by the patent, in view of this, the creator of the present invention has continuously developed a set of inventions different from the above-mentioned prior art. .

The main object of the present invention is to provide a method and system for measuring the channel accuracy of a crossed roller bearing, mainly by setting the function of the motor current collecting, and using the cross roller bearing roller and the channel to form a negative clearance. The characteristics of the cross-roller bearing can be obtained by the motor current collecting technology corresponding to the frictional resistance of the servo motor unit. The technical means for achieving the main object of the present invention is to drive the cross roller bearing to rotate by a servo motor unit. The current input module captures the current signal of the servo motor unit on the time axis. Then, the operation control unit reads the current signal, and records the current signal as the current time domain signal; and uses the fast Fourier The conversion module converts the current time domain signal into a frequency domain signal, and then determines the detection quality information of the crossed roller bearing by the characteristics of the frequency domain signal, wherein the detection quality information is selected from the channel roundness of the crossed roller bearing, At least one of the roller diameter size variation rate, channel roughness, and assembly accuracy.

1‧‧‧cross roller bearing

10‧‧‧Servo motor unit

20‧‧‧current input module

30‧‧‧Operation Control Unit

11‧‧‧Motor drive

12‧‧‧Servo motor

120‧‧‧ Output shaft

31‧‧‧Electromechanical controller

32‧‧‧Signal transmission module

33‧‧‧ computer equipment

40‧‧‧Power supply

50‧‧‧Drive interface

FIG. 1 is a schematic diagram of a functional block implementation of a specific architecture of the present invention.

2 is a schematic diagram of the implementation of a specific circuit architecture of the present invention.

In order to allow the reviewing committee to further understand the technical features of the present invention and the technical means for achieving the object of the present invention, it will be described in detail by way of specific embodiments and drawings: please refer to FIGS. 1 to 2 to achieve the present invention. The main purpose embodiments include a servo motor unit 10, a current input module 20, and an arithmetic control unit 30. The present invention mainly provides a fast Fourier transform module (FFT; and a software having a fast Fourier transform method) built in the arithmetic control unit 30. Next, the servo motor unit 10 drives the cross roller bearing 1 to rotate; and the current input module 20 captures the current signal of the servo motor unit 10 on a time axis (about 20 seconds to 15 minutes); The unit 30 reads the current signal and records the current signal as a curve corresponding to the time axis. Here, the current time domain signal of the curve is obtained; and then, the current time is measured by the fast Fourier transform module (FFT). The domain signal is converted into a frequency domain signal, and then a known bearing accuracy frequency domain signal feature has been established for one of the conventional bearing analysis and detection technologies (ie, channel roundness, roller outer diameter accuracy, and frequency distribution characteristics are compared) The detection data judgment technique such as the channel roughness determines whether the detection quality information of the crossed roller bearing 1 conforms to the standard (which may be indicated by information or not), and the detection quality information may refer to Whether the channel roundness of the crossed roller bearing 1 conforms to the standard, whether the diameter variability of the roller conforms to the standard, whether the channel roughness and the assembly accuracy conform to one of the standards.

In addition, it must be noted that, due to the above-mentioned frequency domain signal feature analysis and detection technology, it has indeed been widely known as detection technology for major bearing manufacturers, so the detailed description of the frequency domain signal feature analysis and detection technology will not be repeated.

Referring to a specific embodiment shown in FIGS. 1 and 2, the servo motor unit 10 includes a motor driver 11 and a servo motor 12. The cross roller bearing 1 is mounted on the output shaft 120 of the servo motor 12 (but not limited thereto), and the motor driver 11 can be driven to rotate the servo motor 12 and the cross roller bearing 1 under the control of the arithmetic control unit 30. Specifically, the current signal is extracted from the input current and output current of the servo motor 12 of the servo motor unit 10.

Referring to a specific embodiment shown in FIG. 1 to FIG. 2, the operation control unit 30 includes an electromechanical controller 31 and a signal transmission module 32 (such as the Internet; or an Ethernet network and a data machine; Or a combination of routers) and a computer device 33. The electromechanical controller 31 is electrically connected to the motor driver 11 and the current input module 20 of the servo motor unit 10 for receiving the current signal transmitted from the current input module 20 and controlling the operation of the motor driver 11. On the other hand, the computer device 33 receives the current signal transmitted from the electromechanical controller 31 through the signal transmission module 32 to record the current signal as a current time domain signal. The Fast Fourier Transform Module (FFT) is built into the computer device 33 to convert the current time domain signal into a frequency domain signal.

Specifically, in the embodiment shown in FIG. 2, the electromechanical controller 31 of the present invention may be a Compact RIO controller, and the power supply required for the Compact RIO controller is supplied by a power supply 40 of the model PS-15. The current input module 20 can be a data picker of the model NI-9227, and the servo motor 12 can be a brushless servo of the model AKM13C. The motor driver 11 can be an AKD motor driver 11, and the AKD motor driver 11 and the Compact RIO controller are electrically connected to a driving interface 50. The driving interface 50 can be a driving interface card of the model NI-9514. The motion module, here, may constitute a specific implementation architecture of the circuit of the present invention.

In a specific detection embodiment of the present invention, the crossed roller bearing 1 is placed on the output shaft 120 of the servo motor 12; then, the current input module 20 is used to capture the current signal of the servo motor 12 (ie, input). The current or the output current; or the input current and the output current are simultaneously taken; and the current control signal is read by the operation control unit 30, and the current signal is recorded as a curve corresponding to the time axis, thereby obtaining the curve. Current time domain signal; Next, the current time domain signal is converted into a frequency domain signal by a fast Fourier transform module (FFT), and then the characteristics of the frequency domain signal are used to determine the detection quality information of the crossed roller bearing 1

Specifically, when the inner ring of the crossed roller bearing 1 is defective and the rolling elements thereof are in contact with the defect, a transient short-lived vibration is generated, and this weak vibration causes the frictional force of the crossed roller bearing 1 to increase, once the cross roll is rolled. The frictional force of the sub-bearing 1 is increased, and the output current signal of the servo motor 12 is synchronously reduced to become smaller, and the load becomes larger, so that the output current signal is output as a current pulse signal similar to the vibration pulse signal of the prior art, and these current pulses After the signal passes through the low-pass filter, the current pulse signal (time domain) can be converted into a frequency domain signal by using the above-mentioned fast Fourier transform module (FFT). Since the current pulse signal is excited after being converted into a frequency domain signal, the current pulse signal is excited. In the frequency band, the frequency band can be from several hundred Hz to several hundred kHz. Here, the frequency domain signal characteristic analysis detection technique (that is, the frequency distribution feature is compared with the channel roundness, What is the judgment technique of the detection data of the outer diameter accuracy of the roller and the channel roughness, etc.) That is, the detection quality information such as channel roundness, roller outer diameter accuracy, and channel roughness.

Therefore, the present invention can be made by the motor by the description of the above specific embodiments. The function of current collecting is set, and the characteristics of the cross-roller bearing roller and the channel are combined with the negative clearance, so as to judge the multiple precision level information of the crossed roller bearing by the bearing frictional resistance, that is, the motor current collecting data. For example, the bearing quality information such as the channel roundness of the bearing, the variation rate of the roller diameter, the channel roughness, and the assembly accuracy.

The above is only a possible embodiment of the present invention, and is not intended to limit the scope of the patents of the present invention, and the equivalent implementations of other changes according to the contents, features and spirits of the following claims should be It is included in the patent of the present invention. The invention is specifically defined in the structural features of the request item, is not found in the same kind of articles, and has practicality and progress, has met the requirements of the invention patent, and has filed an application according to law, and invites the bureau to approve the patent according to law to maintain the present invention. The legal rights of the applicant.

Claims (9)

A method for measuring channel accuracy of a crossed roller bearing, comprising: providing a servo motor unit, a current input module, an arithmetic control unit and a crossed roller bearing; wherein the arithmetic control unit has a built-in fast Fourier a conversion module (FFT); driving the cross roller bearing rotation by the servo motor unit; the current input module captures a current signal of the servo motor unit on a time axis, wherein the current signal is selected from the selection An input current and an output current of one of the servo motor units, and simultaneously extracting one of the input current and the output current; and reading the current signal by the operation control unit, and recording the current signal as a pair The current time domain signal is obtained from the curve of the time axis; and the current time domain signal is converted into the frequency domain signal by the fast Fourier transform module (FFT), and the frequency domain signal is characterized by a bearing analysis and detection technology. A known bearing accuracy frequency domain signal characteristic comparison is established to determine whether the detection quality information of the crossed roller bearing is in compliance with the standard information. The method for measuring the channel accuracy of a crossed roller bearing according to claim 1, wherein the detection quality information is selected from whether the channel roundness of the crossed roller bearing conforms to a standard, the roller of the crossed roller bearing. Whether the diameter variation rate is in compliance with the standard, whether the channel roughness of the crossed roller bearing conforms to the standard, and whether the matching accuracy of the crossed roller bearing conforms to the standard information is at least one of the information. The method of measuring the channel accuracy of a cross roller bearing according to claim 1, wherein the servo motor unit comprises a motor driver and a servo motor; the crossed roller bearing is mounted on an output shaft of the servo motor The motor driver is controlled by the arithmetic control unit to drive the servo motor and the cross roller bearing to rotate. The method for measuring the channel accuracy of a cross roller bearing according to claim 1, wherein the operation control unit comprises an electromechanical controller, a signal transmission module and a computer device; The controller is electrically connected to the motor driver and the current input module of the servo motor unit for receiving the current signal transmitted from the current input module and controlling the operation of the motor driver; The signal transmission module receives the current signal transmitted by the electromechanical controller to record the current signal as a current time domain signal; and the fast Fourier transform module converts the current time domain signal into a frequency domain signal. A method for measuring the channel accuracy of a crossed roller bearing as described in claim 4, wherein the fast Fourier transform module (FFT) is built in the computer device to convert the current time domain signal to the frequency Domain signal. A system for measuring channel accuracy of a crossed roller bearing, comprising: a servo motor unit for driving a cross roller bearing rotation; and a current input module for capturing the servo in a time axis a current signal of the motor unit; an arithmetic control unit having a fast Fourier transform module (FFT) built therein, the operation control unit reading the current signal of the time axis, and recording the current signal as corresponding to the time axis The curve is obtained to obtain a current time domain signal, and the current time domain signal is converted into a frequency domain signal by the fast Fourier transform module (FFT), and the frequency domain signal is characterized by a bearing analysis and detection technology. It is known that the bearing precision frequency domain signal characteristic comparison determines whether the detection quality information of the crossed roller bearing is in compliance with the standard information; wherein the detection quality information is selected from whether the channel roundness of the crossed roller bearing matches Standard information, whether the diameter variation rate of the roller of the crossed roller bearing meets the standard information, whether the channel roughness of the crossed roller bearing conforms to the standard Information and whether the accuracy of the matching of the crossed roller bearings meets at least one of the standard information. The system for measuring the channel accuracy of a crossed roller bearing according to claim 6, wherein the servo motor unit comprises a motor driver and a servo motor; the crossed roller bearing is mounted on an output shaft of the servo motor. The motor driver can be driven by the arithmetic control unit to drive the servo The motor and the crossed roller bearing rotate. The system for measuring the channel accuracy of a cross roller bearing according to claim 7, wherein the operation control unit comprises an electromechanical controller, a signal transmission module and a computer device; the electromechanical controller and the servo motor respectively The motor driver and the current input module are electrically connected to receive the current signal transmitted from the current input module and control the operation of the motor driver; the computer device receives the signal through the signal transmission module The current signal transmitted by the electromechanical controller is used to record the current signal as a current time domain signal; the fast Fourier transform module (FFT) is built in the computer device to convert the current time domain signal into a frequency domain signal . The system for measuring the channel accuracy of a crossed roller bearing as described in claim 8, wherein the electromechanical controller is electrically connected to the motor driver through a driving interface.