Device and method for in-situ detection of shaft coaxiality based on optical dynamic reference coupling

Abstract

The invention relates to an in-situ detection device and method for shaft coaxiality coupled with an optical dynamic reference, and relates to the field of shaft error detection. It solves the problems of offline measurement reference distortion, spatial accessibility limitations of contact measurement, and lack of adaptability to dynamic working conditions in traditional measurement methods. The device includes a first retaining ring, a shaft, a bearing sleeve, a second retaining ring, and a photosensitive position sensor. The first retaining ring is coaxially fixedly connected to the left end of the shaft via a flange structure. Its stator is connected to the motor adapter plate via screws. The bearing sleeve is sleeved on the right end of the shaft, with its inner wall rigidly fitting the outer ring of the bearing, and the shaft and the inner ring of the bearing have an interference fit. The second retaining ring is coaxially fixedly connected to the end face of the bearing sleeve via a flange structure. The photosensitive position sensor is vertically fixed to the axial end face of the second retaining ring via a rigid mounting frame, with its photosensitive surface facing the axis of the shaft. This invention is also applicable to the field of dynamic error detection of optical-mechanical systems such as aerospace optoelectronic pods and high-precision CNC turntables.

Description

Technical Field

[0001] The present invention relates to the field of shafting error detection, and in particular to a shafting coaxiality in-situ detection device and method using optical dynamic reference coupling. Background Art

[0002] Shaft coaxiality is a core indicator of the dynamic performance of high-precision rotary systems (such as aerospace power units and precision machine tool spindles). Its measurement accuracy directly affects the service reliability and lifespan of the equipment. Currently, the industrial inspection field mainly relies on equipment such as coordinate measuring machines and laser trackers to calibrate shaft system form and position tolerances. However, existing shaft coaxiality inspection technologies have the following systemic flaws:

[0003] Offline measurement datum distortion: Traditional CMMs require the shafting under test to be disassembled and taken to a laboratory for offline measurement. This disassembly releases assembly stresses, leading to elastic deformation errors. Furthermore, a systematic offset occurs between the measurement datum and the shafting's actual operating datum, making the measurement results inaccurate and unable to reflect the actual deformation under service conditions.

[0004] Spatial accessibility limitations of contact measurement: Contact measurement methods such as mechanical probes require sufficient unobstructed operating space along the measurement path, making in-situ online inspection impossible in compact shafting assemblies (such as aircraft engine rotor cavities).

[0005] Lack of adaptability to dynamic working conditions: When the rotating shaft system is in variable speed working conditions or continuous operation, non-contact equipment such as laser trackers cannot achieve high-precision real-time coaxiality characterization due to insufficient measurement synchronization and limited dynamic tracking capabilities. Summary of the Invention

[0006] In response to the above bottlenecks, existing technologies have not yet overcome the coupling problem of disassembly deformation-spatial constraints-dynamic mismatch. There is an urgent need for an in-situ detection method that can realize synchronous measurement of dynamic working conditions in compact assemblies.

[0007] Solution 1: The present invention proposes an optical dynamic reference coupling shaft coaxiality in-situ detection device, the device comprising a first retaining ring, a shaft, a motor, a motor adapter plate, a bearing sleeve, a second retaining ring, a bearing, a photosensitive position sensor, and a laser;

[0008] The first retaining ring is coaxially fixedly connected to the left end of the shaft through a flange structure; the rotor of the motor is axially fixed to the shaft through screws, and its stator is connected to the motor adapter plate through screws; the bearing sleeve is sleeved on the right end of the shaft, its inner wall is rigidly fitted with the outer ring of the bearing, and the shaft and the inner ring of the bearing are interference fit; the second retaining ring is coaxially fixedly connected to the end face of the bearing sleeve through a flange structure; the photosensitive position sensor is vertically fixed to the axial end face of the second retaining ring through a rigid mounting frame, and its photosensitive surface faces the axis direction of the shaft.

[0009] Furthermore, a preferred embodiment is provided, wherein the motor adapter plate and the motor are an integrated structure.

[0010] Furthermore, a preferred embodiment is provided, wherein the laser is a small-aperture laser with an ultra-narrow divergence angle.

[0011] Furthermore, a preferred embodiment is provided, wherein the center position of the photosensitive position sensor is the reference axis of the shaft and the bearing sleeve.

[0012] Solution 2: A method for in-situ detection of shaft coaxiality using optical dynamic reference coupling. The method is implemented based on the device described in Solution 1 and includes the following steps:

[0013] Step 1: When the shaft is the reference axis and the bearing sleeve is the non-reference axis, the shaft rotates to form a spot curve. The spot coordinate sequence is collected in real time by the photosensitive position sensor to construct the spatial error motion trajectory envelope and calculate the trajectory point set {P i (x i ,y i )} Maximum radial offset to the reference axis , and judge Whether the design tolerance D is not exceeded;

[0014] Step 2: When the shaft is the non-reference axis and the bearing sleeve is the reference axis, repeat step 1;

[0015] Step 3. Repeat steps 1 to 2 to complete the in-situ detection of the shafting coaxiality.

[0016] Furthermore, a preferred embodiment is provided, wherein the maximum radial offset The calculation method is .

[0017] The present invention is beneficial in that:

[0018] The optical dynamic reference coupled shaft coaxiality in-situ detection device and method described in the present invention use an ultra-narrow divergence angle laser and a high-rigidity silicon carbide ceramic retaining ring to construct a dynamic reference optical path, avoiding errors caused by stress deformation in traditional mechanical contact measurement and ensuring the absolute stability of the measurement reference.

[0019] The in-situ detection device and method for shaft coaxiality using optical dynamic reference coupling, described in this invention, achieves ultra-high-precision measurement. Equipped with advanced photosensitive position sensors, they accurately capture the trajectory of the light spot in real time, achieving submicron position resolution. This significantly improves accuracy compared to traditional micrometers (accuracy of ±5μm) and coordinate measuring machines.

[0020] The present invention utilizes axis rotation to generate the light spot trajectory envelope surface, and directly characterizes the coaxiality error through the maximum radial offset Δmax, effectively eliminating the influence of the cumulative error in the traditional multi-section fitting method, and the measurement result is more accurate and reliable.

[0021] The in-situ shaft coaxiality detection device described in this invention directly installs a retaining ring and a light-sensitive position sensor on the working shaft, eliminating the need for equipment disassembly. This makes the detection process simple and quick. Compared to offline testing on a CMM, it significantly improves efficiency, significantly reduces downtime, and increases production efficiency.

[0022] The in-situ detection device for shaft coaxiality described in the present invention supports synchronous data collection while the turntable is in operation, can monitor the dynamic changes of the shaft system in real time, and provide strong support for real-time adjustment and optimization of the equipment.

[0023] The laser and photosensitive position sensor described in this invention are highly integrated into a silicon carbide ceramic retaining ring, resulting in a compact overall design. This makes them particularly suitable for small assembly clearances in demanding applications, such as aerospace optoelectronic pods, and offer exceptional flexibility. The photosensitive position sensor records coordinate sequences in real time, accurately analyzing dynamic error components such as eccentricity and oscillation during shaft rotation, providing comprehensive data support for equipment performance evaluation and optimization. Direct testing at the equipment's rated speed and load accurately reflects the combined error of assembly deformation and bearing clearance, providing more practical reference value than data obtained under ideal laboratory conditions.

[0024] The detection results of the in-situ detection method for shaft coaxiality using optical dynamic reference coupling described in the present invention can directly guide the adjustment of gasket thickness or bolt preload, avoiding the time waste and potential risks caused by repeated disassembly and assembly in traditional measurement methods, and significantly improving assembly efficiency and quality.

[0025] The present invention is also applicable to the field of dynamic error detection of optical-mechanical systems such as aerospace optoelectronic pods and high-precision CNC turntables. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the in-situ detection device for shaft coaxiality of optical dynamic reference coupling described in embodiment 1.

[0027] Among them, there are a first retaining ring 1, a shaft 2, a motor 3, a motor adapter plate 4, a bearing sleeve 5, a second retaining ring 6, a bearing 7, and a photosensitive position sensor 8. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the implementation methods of this application clearer, the technical solutions in the implementation methods of this application will be clearly and completely described below in combination with the drawings in the implementation methods of this application. Obviously, the described implementation methods are only part of the implementation methods of this application, not all of the implementation methods.

[0029] Embodiment 1. This embodiment provides an optical dynamic reference coupling shaft coaxiality in-situ detection device, the device comprising a first retaining ring 1, a shaft 2, a motor 3, a motor adapter plate 4, a bearing sleeve 5, a second retaining ring 6, a bearing 7, a photosensitive position sensor 8, and a laser;

[0030] The first retaining ring 1 is coaxially fixedly connected to the left end of the shaft 2 through a flange structure; the rotor of the motor 3 is axially fixed to the shaft 2 by screws, and its stator is connected to the motor adapter plate 4 by screws; the bearing sleeve 5 is sleeved on the right end of the shaft 2, and its inner wall is rigidly fitted with the outer ring of the bearing 7, and the shaft 2 and the inner ring of the bearing 7 are interference fit; the second retaining ring 6 is coaxially fixedly connected to the end face of the bearing sleeve 5 through a flange structure; the photosensitive position sensor 8 is vertically fixed to the axial end face of the second retaining ring 6 through a rigid mounting frame, and its photosensitive surface faces the axial direction of the shaft 2.

[0031] Embodiment 2: This embodiment further limits the shaft coaxiality in-situ detection device of optical dynamic reference coupling described in Embodiment 1. The motor adapter plate 4 and the motor 3 are an integrated structure.

[0032] Implementation method 3: This implementation method further limits the in-situ detection device for shaft coaxiality of optical dynamic reference coupling described in implementation method 1. The laser is a small-aperture laser with a narrow divergence angle.

[0033] Embodiment 4: This embodiment further limits the optical dynamic reference coupled shaft coaxiality in-situ detection device described in Embodiment 1. The center position of the photosensitive position sensor 8 is the reference axis of the shaft 2 and the bearing sleeve 5.

[0034] Embodiment 5: This embodiment proposes an in-situ detection method for shaft coaxiality using optical dynamic reference coupling. The method is implemented based on the device described in embodiment 1 and includes the following steps:

[0035] Step 1: When shaft 2 is used as the reference axis and bearing sleeve 5 is used as the non-reference axis, shaft 2 rotates to form a spot curve. The light spot coordinate sequence is collected in real time by the photosensitive position sensor 8 to construct the spatial error motion trajectory envelope and calculate the trajectory point set {P i (x i ,y i )} Maximum radial offset to the reference axis , and judge Whether the design tolerance D is not exceeded;

[0036] Step 2: When shaft 2 is used as the non-reference axis and bearing sleeve 5 is used as the reference axis, repeat step 1;

[0037] Step 3. Repeat steps 1 to 2 to complete the in-situ detection of the shafting coaxiality.

[0038] Implementation 6: This implementation is a further limitation of the in-situ detection method of the axis coaxiality of the optical dynamic reference coupling described in Implementation 5. The calculation method is .

[0039] Embodiment 7. This embodiment provides the following examples to explain the above-mentioned embodiments 1 to 6. The specific examples are as follows:

[0040] See also Figure 1 As shown, in the optical dynamic reference coupled shaft coaxiality in-situ detection device described in the first embodiment, the first retaining ring 1 is coaxially fixedly connected to the left end of the shaft 2 through a flange structure; the rotor of the motor 3 is axially fixed to the shaft 2 by screws, and its stator is connected to the motor adapter plate 4 by screws; the bearing sleeve 5 is sleeved on the right end of the shaft 2, and its inner wall is rigidly fitted with the outer ring of the bearing 7, and the shaft 2 and the inner ring of the bearing 7 are interference fit; the second retaining ring 6 is coaxially fixedly connected to the end face of the bearing sleeve 5 through a flange structure; the photosensitive position sensor 8 is vertically fixed to the axial end face of the second retaining ring 6 through a rigid mounting frame, and its photosensitive surface is facing the axial direction of the shaft 2.

[0041] Among them, a high-rigidity silicon carbide ceramic standard retaining ring is installed on the end face of the shaft system, and a small-aperture laser with an ultra-narrow divergence angle is used to generate a reference light spot. A high-rigidity silicon carbide ceramic standard retaining ring is installed on the other side of the shaft, and the photosensitive position sensor is installed in the center to record the center position as the reference axis.

[0042] The laser light penetrates the through hole of the clamping ring and forms a light spot on the photosensitive position sensor. The axis rotates to form a light spot curve. The light spot coordinate sequence is collected in real time to construct the envelope surface of the spatial error motion trajectory.

[0043] Calculate the maximum radial offset of the bearing sleeve trajectory point set to the reference axis , where the error analysis algorithm is:

[0044] The non-reference axis trajectory point set {P i (x i ,y i )} mapped to the reference coordinate system;

[0045] Calculate the maximum radial offset ;

[0046] The judgment condition is ≤Design tolerance D.

[0047] In summary, the in-situ detection device and method for shaft coaxiality using optical dynamic reference coupling described in this embodiment can achieve ultra-high-precision measurement. Equipped with advanced photosensitive position sensors, they accurately capture the light spot trajectory in real time, achieving sub-micron position resolution. This significantly improves accuracy compared to traditional micrometers (accuracy of ±5μm) and coordinate measuring machines.

[0048] This embodiment uses shaft rotation to generate the light spot trajectory envelope surface, and directly characterizes the coaxiality error through the maximum radial offset Δmax, effectively eliminating the influence of cumulative errors in the traditional multi-section fitting method, and the measurement results are more accurate and reliable.

[0049] This implementation enables in-situ, online inspection of compact shafting assemblies. In dynamic measurement environments, the laser tracker offers a more flexible solution than contact measurement, particularly in scenarios where contact must be avoided. Furthermore, on production lines or in situations requiring rapid inspection, the laser tracker can quickly provide measurement results, improving work efficiency and enabling high-precision, real-time coaxiality characterization.

[0050] Those skilled in the art will appreciate that the features described in the various embodiments and / or technical solutions of this disclosure may be combined or coupled in various ways, even if such combinations or couplings are not explicitly described in this disclosure. In particular, the various embodiments of this disclosure may be combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations fall within the scope of this disclosure.

[0051] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as covering the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the present invention and its equivalents.

Claims

1. The optical dynamic reference coupling shaft coaxiality in-situ detection device is characterized by: The device comprises a first retaining ring (1), a shaft (2), a motor (3), a motor adapter plate (4), a bearing sleeve (5), a second retaining ring (6), a bearing (7), a photosensitive position sensor (8), and a laser; The first retaining ring (1) is coaxially fixedly connected to the left end of the shaft (2) through a flange structure; the rotor of the motor (3) is axially fixedly connected to the shaft (2) through screws, and its stator is connected to the motor adapter plate (4) through screws; the bearing sleeve (5) is sleeved on the right end of the shaft (2), the inner wall of which is rigidly fitted with the outer ring of the bearing (7), and the shaft (2) and the inner ring of the bearing (7) are interference fit; the second retaining ring (6) is coaxially fixedly connected to the end face of the bearing sleeve (5) through a flange structure; the photosensitive position sensor (8) is vertically fixed to the axial end face of the second retaining ring (6) through a rigid mounting frame, and its photosensitive surface faces the axial direction of the shaft (2).

2. The optical dynamic reference coupling shaft coaxiality in-situ detection device according to claim 1 is characterized in that: The motor adapter plate (4) and the motor (3) are an integrated structure.

3. The optical dynamic reference coupling shaft coaxiality in-situ detection device according to claim 1, characterized in that: The laser is a small-aperture laser with an ultra-narrow divergence angle.

4. The optical dynamic reference coupling shaft coaxiality in-situ detection device according to claim 1, characterized in that: The center position of the photosensitive position sensor (8) is the reference axis of the shaft (2) and the bearing sleeve (5).

5. The in-situ detection method of shaft coaxiality based on optical dynamic reference coupling is characterized by: The method is implemented based on the device according to claim 1, and the method comprises the following steps: Step 1: When the shaft (2) is used as the reference axis and the bearing sleeve (5) is used as the non-reference axis, the shaft (2) rotates to form a light spot curve, and the light spot coordinate sequence is collected in real time by the photosensitive position sensor (8), and the spatial error motion trajectory envelope is constructed to calculate the trajectory point set {P i (x i ,y i )} Maximum radial offset to the reference axis , and judge Whether the design tolerance D is not exceeded; Step 2: When the shaft (2) is used as the non-reference shaft and the bearing sleeve (5) is used as the reference shaft, repeat step 1; Step 3, repeat step 1 to step 2, and compare the maximum radial offset of the trajectory point set generated by rotating the light spot curve with the axis (2) as the reference axis and the bearing sleeve (5) as the non-reference axis. , complete the in-situ detection of shaft coaxiality.

6. The in-situ detection method for shaft coaxiality of optical dynamic reference coupling according to claim 5 is characterized in that: The maximum radial offset The calculation method is .

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