A wide range, high precision instantaneous speed sensor and measurement method

Abstract

A wide-range, high-precision instantaneous speed sensor and measurement method, comprising: a broadband light source, a fiber coupler, a spectrometer, a signal processing device, a signal detection arm, a signal reference arm and a rotating shaft; the rotating shaft comprises: a cylindrical shaft portion and a topographic processing portion, the radius of the topographic processing portion changes periodically; the broadband light source, the spectrometer, the signal detection arm and the signal reference arm are respectively connected to the fiber coupler via optical fibers; the spectrometer is connected to the signal processing device; the signal detection arm is aligned with the topographic processing portion of the rotating shaft; the signal reference arm is aligned with the cylindrical shaft portion of the rotating shaft; the light emitted by the broadband light source is divided into two beams by the fiber coupler; the fiber coupler superimposes the two beams of light returned to generate an interference fringe signal; the signal processing device obtains the rotation angle and speed information of the rotating shaft through processing. The present invention provides a wide-range, high-precision instantaneous speed sensor and measurement method.

Description

Technical Field

[0001] The invention belongs to the technical field of rotation speed measurement, and specifically refers to a wide-range, high-precision instantaneous rotation speed sensor and a measurement method. Background Art

[0002] Speed ​​is the core parameter in the monitoring of the operation status of mechanical transmission systems and rotating machinery. Speed ​​measurement is of vital importance for the performance optimization and safety assurance of equipment in high-precision and cutting-edge fields. The demand for high-precision real-time monitoring of dynamic operating parameters in modern mechanical systems has increased significantly, and the limitations of traditional methods in dynamic response, instantaneous accuracy and adaptability to complex working conditions have become increasingly prominent. In the field of aerospace, high-precision speed measurement is widely used in aircraft propulsion systems, aircraft engine performance optimization and attitude control. Especially under extreme conditions such as high temperature and high vibration, speed monitoring is the key to ensuring the stable operation of equipment. In the energy field, dynamic speed monitoring in wind power generation and nuclear power equipment directly affects power generation efficiency and system safety, while in rail transportation, high-speed trains and maglev trains rely on real-time speed measurement to optimize dynamic balance and performance adjustment. In addition, medical equipment such as surgical robots and artificial heart pumps, as well as drone control and missile guidance systems in the military field, also require instantaneous speed monitoring with high dynamic response capabilities to support high-precision and real-time operation requirements.

[0003] Traditional speed measurement technologies are generally divided into two categories: contact and non-contact. Contact speed measurement technology (such as mechanical centrifugal tachometers) obtains speed information by directly connecting to rotating parts. Its structure is relatively simple, but it has obvious disadvantages. Since direct contact will cause mechanical wear, the measurement accuracy and service life of the contact method will decrease significantly with the increase of operating time. In addition, contact sensors usually add additional mass to the equipment, which may have an adverse effect on the dynamic characteristics of the rotating parts, especially in high-dynamic scenarios, this additional burden is more prominent. Therefore, contact measurement methods are difficult to meet the needs of modern industry for high-precision and long-life measurement devices.

[0004] Non-contact speed measurement technology has become the mainstream direction of modern industrial applications because it does not need to directly contact the rotating parts, avoids mechanical wear problems, has higher reliability and flexibility, and has become the mainstream direction of modern industrial applications. Common non-contact methods include photoelectric speed encoders, magnetic induction sensors, Doppler effect sensors, and optical interference sensors. Among them, the photoelectric encoder uses the engraved disk on the rotating shaft to detect the change of the rotation angle through the photoelectric sensor to calculate the speed, which has high accuracy and resolution. However, its measurement accuracy is limited by the density of the engraved lines and the size of the light source. When measuring at ultra-low speeds, it is difficult to achieve high-precision detection of the instantaneous speed due to the large interval of the pulse signal. The magnetic induction sensor obtains speed information by detecting the change of the magnetic field caused by the rotating parts. It has a fast response speed, but is easily disturbed by the external magnetic field. At the same time, it has certain requirements for the rotor surface material and needs to add ferromagnetic materials to improve the measurement sensitivity. It has poor applicability in complex electromagnetic environments. The electrostatic tachometer measures the speed by detecting the change of the static charge on the surface of the rotating shaft. It can achieve non-contact measurement under certain specific conditions, but its performance is easily limited by the insufficient static charge on the rotor surface and cannot work stably in a low-charge or no-charge environment. The Doppler effect sensor uses the laser Doppler effect to calculate the rotational speed by detecting the frequency change of the laser reflection on the rotating surface. It is a highly sensitive non-contact measurement method. However, when stationary or running at low speed, the Doppler frequency shift signal is weak or even disappears, resulting in a significant decrease in the system's detection capability, limiting its application under ultra-slow speed conditions. Optical interferometric sensors are based on the wave characteristics of light and calculate the rotational speed information by detecting the phase change of interference fringes. They have high precision and good non-contact performance. However, traditional optical interference methods usually use a single-beam detection light design, which is easily affected by the eccentricity and vibration of the rotating shaft, resulting in large measurement errors. At the same time, there are still technical bottlenecks in dynamic response and wide range adaptability.

[0005] Existing speed sensors have significant limitations in their range. When measuring at low speeds, magnetoelectric sensors are insensitive to weak signals, the pulse interval of photoelectric encoders is too large, and the frequency shift signal of Doppler effect sensors is weak, making it difficult to achieve high-precision detection. In high-speed measurements, contact sensors are limited in performance due to mechanical wear and heat accumulation, and non-contact sensors may be inaccurate due to dynamic blur or insufficient signal processing capabilities. In addition, traditional sensors are sensitive to vibration, eccentricity, and environmental interference, making it difficult to adapt to complex working conditions, and cannot maintain high-precision measurements at both low and high speeds.

[0006] Although existing contact and non-contact speed measurement technologies have their own advantages, they still cannot fully meet the requirements of modern industry for high accuracy, wide range, dynamic real-time response, and adaptability to complex working conditions. At the same time, complex installation and high maintenance costs also limit the application of these technologies in dangerous or harsh environments. Therefore, designing a reliable, efficient, and adaptable non-contact speed measurement method is of great significance to address the shortcomings of existing technologies. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a wide-range, high-precision instantaneous rotation speed sensor and a measuring method.

[0008] The present invention is achieved in that:

[0009] A wide-range, high-precision instantaneous rotation speed sensor, comprising: a broadband light source, an optical fiber coupler, a spectrometer, a signal processing device, a signal detection arm, a signal reference arm and a rotating shaft;

[0010] The rotating shaft comprises: a cylindrical shaft portion and a shape processing portion, wherein the radius of the shape processing portion changes periodically;

[0011] The broadband light source, the spectrometer, the signal detection arm and the signal reference arm are respectively connected to the optical fiber coupler via optical fibers; the spectrometer is connected to the signal processing device;

[0012] The signal detection arm is aligned with the topographic processing portion of the rotating shaft;

[0013] The signal reference arm is aligned with the cylindrical shaft portion of the rotating shaft;

[0014] The light emitted by the broadband light source is divided into two beams through the optical fiber coupler: one beam is detection light, which is transmitted to the topography processing part through the signal detection arm and returns to the optical fiber coupler after reflection; the other beam is reference light, which is transmitted to the cylindrical shaft through the signal reference arm and also returns to the optical fiber coupler after reflection;

[0015] The detection light and the reference light are located at the same height on the surface of the rotating shaft, and the optical paths are symmetrical;

[0016] The optical fiber coupler superimposes the two returning light beams to generate an interference fringe signal;

[0017] The signal processing device is used to sample and analyze the interference fringes to obtain the rotation angle and speed information of the rotating shaft in real time.

[0018] Furthermore, the radius of the topography processed portion changes linearly or sinusoidally periodically.

[0019] Furthermore, the topography processing portion is located at any position of the end or middle of the cylindrical shaft portion.

[0020] Furthermore, the topography processing portion and the cylindrical shaft portion are integrally formed or sleeved.

[0021] A method for measuring a wide-range, high-precision instantaneous rotation speed sensor comprises the following steps:

[0022] During the rotation of the shaft, the reference light is irradiated on the smooth surface of the cylindrical shaft, and its reflected optical path is kept constant; the detection light is irradiated on the area of ​​the topography processing part, and its reflected optical path changes periodically with the rotation;

[0023] The wavelength detection range of the spectrometer is λ1-λ2, and its spectrum resolution is The relationship with the wavelength range satisfies the formula: (1)

[0024] In the formula, is the refractive index of the medium;

[0025] By designing the radius variation of the topography processing portion, the angular displacement introduced by the circular motion is modulated into a periodic variation of the surface profile radius, so that it causes a continuous variation of the optical path depth during the rotation process, thereby forming a periodic waveform signal;

[0026] Assume that the shaft rotates once to generate The wave signal of a cycle, then the contour radius function of the rotating shaft with radius R in a single cycle is The following relations are satisfied: (2)

[0027] In the formula is the maximum value of radius change within a cycle, is the angle value of half a cycle;

[0028] The minimum angular resolution of the rotating axis is: (3)

[0029] The sampling interval time range is , then the minimum discernible speed change between adjacent sampling points is and maximum speed change for:

[0030] (4)

[0031] (5)

[0032] From formula (3) and formula (5), we can know that (6)

[0033] The speed and acceleration calculations satisfy the following conditions in a single cycle:

[0034] (7)

[0035] (8)

[0036] In the formula is the displacement coefficient, is the maximum value of the contour radius change, is the number of contour cycles of the designed topography processing part, is the angle value of half a cycle, is the initial speed, is the acceleration;

[0037] By fitting the collected data, we can get and The functional relationship between them is obtained by using various coefficients to obtain the initial speed and acceleration, and then using the obtained acceleration and initial speed Get the speed n at any time t:

[0038] n=a n *t+n0 (9).

[0039] The advantages of the present invention are:

[0040] 1. The present invention significantly expands the measuring range through high sensitivity and differential design, and realizes high-precision measurement from ultra-low speed to ultra-high speed. At the same time, it has the advantages of strong anti-interference ability, fast real-time response, and high environmental adaptability. It overcomes the limitations of traditional technology and provides a reliable solution for dynamic monitoring under complex working conditions.

[0041] 2. The present invention does not rely on pulse interval signals, but captures speed changes in real time by detecting tiny optical path changes, thus avoiding the "pulse interval blank period" problem of the photoelectric encoder at low speeds. Its high sensitivity enables it to output stable and high-precision measurement results even under ultra-low speed conditions.

[0042] 3. The present invention obtains rotation speed information by detecting the change of interference fringes between the light and the reference light. The frequency of the signal is extremely high, independent of the limitation of mechanical rotating parts, and completely determined by the sampling frequency of optical and electronic signals, and can capture subtle changes in ultra-high-speed rotation in real time. Traditional contact sensors are prone to failure at ultra-high speeds due to mechanical friction and heat accumulation, while optical coherence technology adopts a completely non-contact design, without friction or wear problems of mechanical parts, and is suitable for long-term operation in ultra-high-speed scenarios.

[0043] 4. The rotating shaft of the present invention is designed as a cylindrical rotating shaft with a topographic processing portion, which has the characteristics of simple structure, high resolution, strong sensitivity, excellent anti-electromagnetic interference ability, high sampling frequency and fast dynamic response speed. It is suitable for a variety of rotation speed measurement scenarios, especially for applications in high-precision and cutting-edge fields.

[0044] 5. The present invention provides a differential wide-range, high-dynamic response, high-precision non-contact speed sensor measurement system based on optical interference. By designing the differential optical path of the detection light and the reference light, the interference signal of the optical path difference of the two beams is used to eliminate the influence of the eccentricity and vibration of the rotating shaft on the measurement results to the greatest extent, significantly improve the measurement accuracy and anti-interference ability, and is suitable for high-precision real-time measurement under ultra-low speed and dynamic conditions. The non-contact design avoids mechanical wear and system interference, and is particularly suitable for complex working conditions such as high temperature and high magnetism, which significantly improves the applicability and reliability of the sensor.

[0045] 6. Compared with the traditional photoelectric encoder, the present invention realizes high-precision analysis of interference signals by designing the differential optical path of the detection light and the reference light. The differential design effectively eliminates the influence of the rotating shaft eccentricity, vibration and environmental interference on the measurement accuracy, greatly improving the reliability and anti-interference ability of the measurement. At the same time, the pulse density of the present invention is significantly improved, with higher resolution and sampling frequency, which can not only realize high-precision measurement, but also is suitable for ultra-low speed detection, expanding the application range of the sensor.

[0046] 7. The present invention only needs one detection light to realize rotation speed measurement, which simplifies the system structure and reduces the complexity of optical path adjustment. The design of the optical fiber optical path further enhances the signal strength, improves the interference effect and measurement accuracy. The combination of the differential optical path and the optical fiber design enables the sensor to have excellent vibration resistance, ensuring its stability and high dynamic response performance in a dynamic environment. By optimizing the optical path and interference conditions, the present invention has significant advantages in ease of operation and system reliability.

[0047] 8. The speed measurement method of the present invention converts the angle detection into the change of the optical path, avoiding the problems of electromagnetic interference, mechanical wear, etc. By optimizing the optical path design and signal processing algorithm, the speed sensor realizes a wide range of measurement from ultra-low speed to ultra-high speed, and has fast dynamic response capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0049] Figure 1 It is a schematic structural diagram of the first embodiment of the rotation speed sensor of the present invention.

[0050] Figure 2It is a schematic diagram of the three-dimensional structure of the rotating shaft in the first embodiment of the rotation speed sensor of the present invention.

[0051] Figure 3 yes Figure 2 main view.

[0052] Figure 4 yes Figure 3 Bottom view of .

[0053] Figure 5 It is a curve diagram showing the change in radius of the topography processed portion of the rotating shaft with respect to the angle in the first embodiment of the rotation speed sensor of the present invention.

[0054] Figure 6 It is a schematic structural diagram of a second embodiment of a rotation speed sensor of the present invention.

[0055] Figure 7 It is a schematic diagram of the three-dimensional structure of the rotating shaft in the second embodiment of the rotation speed sensor of the present invention.

[0056] Figure 8 yes Figure 7 main view.

[0057] Fig. 9 yes Figure 8 Bottom view of .

[0058] Fig.10 It is a curve diagram showing the change in radius of the topography-processed portion of the rotating shaft with respect to the angle in the second embodiment of the rotation speed sensor of the present invention.

[0059] Fig.11 It is a schematic diagram of another design structure of the rotating shaft of the second embodiment of the rotation speed sensor of the present invention.

[0060] Fig.12 It is a schematic diagram of another design structure of the rotating shaft of the second embodiment of the rotation speed sensor of the present invention. DETAILED DESCRIPTION

[0061] First embodiment: Figures 1 to 4 As shown, a wide-range, high-precision instantaneous rotation speed sensor comprises: a broadband light source 1, a fiber coupler 3, a spectrometer 4, a signal processing device 5, a signal detection arm 7, a signal reference arm 8 and a rotating shaft 6;

[0062] The rotating shaft 6 includes: a cylindrical shaft portion 61 and a topography processing portion 62. The radius of the topography processing portion 62 in this embodiment changes linearly periodically (eg Figure 5 shown);

[0063] The broadband light source 1, the spectrometer 4, the signal detection arm 7 and the signal reference arm 8 are respectively connected to the optical fiber coupler 3 via the optical fiber 2; the spectrometer 4 is connected to the signal processing device 5;

[0064] The signal detection arm 7 is aligned with the topography processing portion 62 of the rotating shaft 6;

[0065] The signal reference arm 8 is aligned with the cylindrical shaft portion 61 of the rotating shaft 6;

[0066] The light emitted by the broadband light source 1 is divided into two beams through the fiber coupler 3: one beam is the detection light, which is transmitted to the topography processing part 62 through the signal detection arm 7, and returns to the fiber coupler 3 after reflection; the other beam is the reference light, which is transmitted to the cylindrical shaft part 61 through the signal reference arm 8, and also returns to the fiber coupler 3 after reflection;

[0067] The detection light and the reference light are located at the same height on the surface of the rotating shaft 6, and the optical paths are symmetrical;

[0068] The optical fiber coupler 3 superimposes the two returning light beams to generate an interference fringe signal;

[0069] The signal processing device 5 is used to sample and analyze the interference fringes to obtain the rotation angle and speed information of the rotating shaft 6 in real time.

[0070] During the rotation of the shaft 6, since the reference light is irradiated on the smooth surface (cylindrical shaft 61), its reflected optical path remains constant; while the detection light is irradiated on the topography processing area (topography processing part 62), its reflected optical path changes periodically with the rotation. Based on this principle, by differentially measuring the interference fringes of the two beams of light, the optical path error caused by installation eccentricity can be effectively eliminated, and the influence of lateral vibration on measurement accuracy during rotation can be significantly suppressed, thereby ensuring the reliability and high-precision performance of the system in a dynamic environment.

[0071] Figures 6 to 9 The figure shows a second embodiment of the rotation speed sensor of the present invention, wherein the radius of the topographic processing portion 62 of the rotating shaft 6 changes in a periodic sinusoidal wave (eg Fig.10 The topographic processing portion 62 of the rotating shaft 6 can be located at any position of the end or middle of the cylindrical shaft portion 61 (such as Fig.11 As shown), and the topography processing portion 62 can be integrally formed or sleeved with the cylindrical shaft 61 (as shown Fig.12 This flexibility ensures the diversity of processing and installation methods, and can meet the requirements of data acquisition and mechanical properties in different scenarios. The speed sensor of the present invention can achieve universality and flexibility in various scenarios through different morphological processing part design schemes, providing a broader space for subsequent optimization and application.

[0072] The measuring methods of the rotation speed sensor in the first embodiment and the second embodiment are as follows:

[0073] For the spectrometer 4 with a wavelength detection range of λ1-λ2, its spectral resolution is The relationship with the wavelength range satisfies the formula: (1)

[0074] In the formula, is the refractive index of the medium. The rotation speed sensor measurement system based on broadband optical coherence in this embodiment is built in the air, and is taken as 1 here.

[0075] Because the speed sensor can only measure the linear displacement along the optical path, for the rotating shaft 6, it is the change of the contour radius of each point on the shaft surface along the optical path. By designing the surface contour radius, the angular displacement introduced by the circular motion is modulated into the periodic change of the surface contour radius, so that it causes the continuous change of the optical path depth during the rotation process, forming a periodic wave signal.

[0076] Assume that shaft 6 rotates once to generate The wave signal of a cycle, then the contour radius function of the rotating shaft 6 with a radius of R in a single cycle is The following relations are satisfied: (2)

[0077] In the formula is the maximum value of radius change within a cycle, is the angle value of half a cycle.

[0078] Therefore, the minimum angular resolution of axis 6 is: (3)

[0079] If the sampling interval time range is , then the minimum discernible speed change between adjacent sampling points is and maximum speed change for:

[0080] (4)

[0081] (5)

[0082] From equations (3) and (5), it can be seen that if the angular resolution of the measurement system (i.e., the speed sensor) is to be improved, the measurement range of the measurement system will become smaller. Therefore, the appropriate surface profile radius design can be selected in combination with the actual application to meet the requirements. The relationship between the two is: (6)

[0083] The speed and acceleration calculation of the measurement system meets the following requirements in a single cycle: (7)

[0084] (8)

[0085] In the formula is the displacement coefficient of the measurement system, is the maximum value of the contour radius change, is the number of designed contour cycles, is the angle value of half a cycle, is the initial speed, is the acceleration.

[0086] by =4, =20 mm, =1 mm, For example, the number of cycles obtained by the measurement system to collect data corresponds to a detection depth change of 5um. The number of cycles corresponding to a 1mm radius change is designed to be 200. The rotation speed and acceleration calculations satisfy the following conditions within a single cycle: ;

[0087] By fitting the collected data, the measurement system can obtain and The functional relationship between them can be used to obtain the initial speed and acceleration through various coefficients, and then use the obtained acceleration and initial speed Get the speed n at any time: n=a n *t+n0 (9).

[0088] If the collected data contains multiple cycles, the M method can be used to calculate the rotational speed by calculating the number of cycles contained in the collection time.

[0089] The present invention provides a differential wide-range, high-dynamic response, high-precision non-contact speed sensor measurement system based on optical interference. By designing the differential optical path of the detection light and the reference light, the interference signal of the optical path difference of the two beams is used to eliminate the influence of the eccentricity and vibration of the rotating shaft on the measurement result to the greatest extent, significantly improve the measurement accuracy and anti-interference ability, and is suitable for high-precision real-time measurement under ultra-low speed and dynamic conditions. The non-contact design avoids mechanical wear and system interference, and is particularly suitable for complex working conditions such as high temperature and high magnetism, which significantly improves the applicability and reliability of the sensor. The present invention only requires one detection light to realize the speed measurement, simplifies the system structure and reduces the complexity of the optical path adjustment. The design of the optical fiber optical path further enhances the signal strength, improves the interference effect and measurement accuracy. The combination of the differential optical path and the optical fiber design enables the sensor to have excellent anti-vibration ability, ensuring its stability and high dynamic response performance in a dynamic environment. By optimizing the optical path and interference conditions, the present invention has significant advantages in terms of ease of operation and system reliability.

[0090] The above embodiments and drawings do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A method for measuring a wide-range, high-precision instantaneous rotation speed sensor, characterized in that: Firstly, an instantaneous rotation speed sensor is provided, comprising: a broadband light source, an optical fiber coupler, a spectrometer, a signal processing device, a signal detection arm, a signal reference arm and a rotating shaft; The rotating shaft comprises: a cylindrical shaft portion and a shape processing portion, wherein the radius of the shape processing portion changes periodically; The broadband light source, the spectrometer, the signal detection arm and the signal reference arm are respectively connected to the optical fiber coupler via optical fibers; the spectrometer is connected to the signal processing device; The signal detection arm is aligned with the topographic processing portion of the rotating shaft; The signal reference arm is aligned with the cylindrical shaft portion of the rotating shaft; The light emitted by the broadband light source is divided into two beams through the optical fiber coupler: one beam is detection light, which is transmitted to the topography processing part through the signal detection arm and returns to the optical fiber coupler after reflection; the other beam is reference light, which is transmitted to the cylindrical shaft through the signal reference arm and also returns to the optical fiber coupler after reflection; The detection light and the reference light are located at the same height on the surface of the rotating shaft, and the optical paths are symmetrical; The optical fiber coupler superimposes the two returning light beams to generate an interference fringe signal; The signal processing device is used to sample and analyze the interference fringes to obtain the rotation angle and speed information of the rotating shaft in real time; The specific measurement method includes the following steps: During the rotation of the shaft, the reference light is irradiated on the smooth surface of the cylindrical shaft, and its reflected optical path is kept constant; the detection light is irradiated on the area of ​​the topography processing part, and its reflected optical path changes periodically with the rotation; The wavelength detection range of the spectrometer is λ1-λ2, and its spectrum resolution is The relationship with the wavelength range satisfies the formula: (1) In the formula, is the refractive index of the medium; By designing the radius variation of the topography processing portion, the angular displacement introduced by the circular motion is modulated into a periodic variation of the surface profile radius, so that it causes a continuous variation of the optical path depth during the rotation process, thereby forming a periodic waveform signal; Assume that the shaft rotates once to generate The wave signal of a cycle, then the contour radius function of the rotating shaft with radius R in a single cycle is The following relations are satisfied: (2) In the formula is the maximum value of radius change within a cycle, is the angle value of half a cycle; The minimum angular resolution of the rotating axis is: (3) The sampling interval time range is , then the minimum discernible speed change between adjacent sampling points is and maximum speed change for: （4） （5） From formula (3) and formula (5), we can know that （6） The speed and acceleration calculations satisfy the following conditions in a single cycle: （7） （8） In the formula is the displacement coefficient, is the maximum value of the contour radius change, is the number of contour cycles of the designed topography processing part, is the angle value of half a cycle, is the initial speed, is the acceleration; By fitting the collected data, we can get and The functional relationship between them is obtained by using various coefficients to obtain the initial speed and acceleration, and then using the obtained acceleration and initial speed Get the speed n at any time t: n=a n *t+n0 (9)。 2. The method for measuring a wide-range, high-precision instantaneous rotation speed sensor according to claim 1, characterized in that: The radius of the topography processing portion changes linearly or sinusoidally periodically.

3. The method for measuring a wide-range, high-precision instantaneous rotation speed sensor according to claim 1, characterized in that: The topography processing portion is located at any position of the end or middle of the cylindrical shaft portion.

4. The method for measuring a wide-range, high-precision instantaneous rotation speed sensor according to claim 1, characterized in that: The topography processing portion and the cylindrical shaft portion are integrally formed or sleeved.

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