A motor shaft hole coaxial degree rapid testing fixture

Abstract

The utility model discloses a motor shaft hole coaxial degree quick gauge, including main platform, be equipped with two parallel first guide slot of each other on the main platform, the first guide slot inside the sliding setting has two bearing plates, and bearing plate is perpendicular to the first guide slot extension direction. The second guide slot is seted up on every bearing plate, and the second guide slot inside the sliding setting has two mounting blocks, and every mounting block is detachably connected with bearing through bolt. The gap is formed between two bearings on the same bearing plate for placing motor shaft, and the bearing outer wall surface is tangent with motor shaft outer wall surface. One end of the first guide slot is equipped with the sliding platform, and the mounting block is detachably fixed on the sliding platform, and the mounting block is provided with the micrometer, and the measuring head of micrometer is inserted into the hole of motor shaft two ends and measures the runout value. Through comparing the value of two micrometers, the motor shaft hole coaxial degree can be evaluated quickly. The utility model discloses simple structure, convenient operation is applicable to the quick detection of processing site.

Description

Technical Field

[0001] This utility model relates to the field of mechanical measurement technology, and in particular to a rapid inspection tool for the coaxiality of the inner hole of a motor shaft, specifically a rapid inspection tool for detecting the coaxiality of the inner hole of a motor shaft. More specifically, this utility model provides a rapid inspection tool for the coaxiality of the inner hole of a motor shaft that is simple in structure, easy to operate, and has high detection efficiency, suitable for rapid detection and parameter adjustment on the machining site. Background Technology

[0002] As a key transmission component in a motor, the coaxiality accuracy of the motor shaft's inner bore directly affects the motor's operational smoothness, noise level, and service life. In the manufacturing and assembly process of motor shafts, inner bore coaxiality is a crucial quality indicator. Currently, precise inspection of the inner bore coaxiality of motor shafts typically employs a coordinate measuring machine (CMM). While CMMs offer high precision and repeatability, their inspection process is complex and time-consuming, usually taking several minutes to tens of minutes, increasing downtime on the production line and impacting overall production efficiency. Furthermore, CMMs are expensive, have stringent environmental requirements, and require specialized operators, making them unsuitable for rapid on-site use.

[0003] In existing technologies, some simple inspection tools are used for coaxiality testing of shaft parts, such as using V-blocks to support the shaft and using dial indicators or micrometers for measurement. However, these methods are generally suitable for testing the coaxiality of external diameters, and are not effective for testing the coaxiality of internal holes. Especially when the motor shaft is long or the internal hole is deep, existing simple inspection tools are difficult to achieve fast and accurate measurements.

[0004] Patent document CN204388765U discloses a gauge for detecting the coaxiality of shaft parts, including a reference base. A pin fixing seat, which is inverted L-shaped, is fixed to the reference base. A pin is fixed to the upper end of the pin fixing seat, and a spherical handle is fixed to the upper end of the pin. A compression spring is fitted onto the pin between the spherical handle and the pin fixing seat. A flared, upward-opening locking inner ring is located directly below the pin. This locking inner ring is fixedly connected to the reference base via a support. A locking outer ring is arranged close to the outer side of the locking inner ring. A rotating ring is threaded between the locking outer ring and the support, and its rotation is controlled by a rotating handle. An outer support seat is also provided on the outer side of the locking outer ring. This invention uses the locking inner ring to lock the workpiece, thereby fixing the workpiece and detecting its coaxiality. However, it is only suitable for measuring the outer diameter of short shafts and cannot effectively detect the coaxiality of inner holes. Furthermore, its structure is complex and costly, making it unsuitable for widespread field use.

[0005] In addition, other attempts exist in existing technologies, such as using laser scanning or optical measurement methods to detect the coaxiality of internal holes. While these methods are non-contact and highly accurate, the equipment is extremely expensive, sensitive to environmental vibration, dust, and temperature changes, making them difficult to use stably on the production site. Furthermore, some pneumatic measurement-based gauges, although fast in response, require complex pneumatic systems and pressure stabilization devices, resulting in high maintenance costs and unsuitability for motor shafts of various sizes.

[0006] In summary, existing technologies lack a tool for quickly, accurately, and cost-effectively detecting the coaxiality of the inner bore of a motor shaft on-site. This invention addresses this technological gap by providing a comprehensive solution through innovative structural design and system integration.

[0007] Therefore, there is an urgent need in this field for a tool that can quickly, easily, and at low cost detect the coaxiality of the inner hole of a motor shaft, in order to solve the problems of long detection time, low efficiency, and high equipment dependence in the existing technology. Utility Model Content

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a rapid inspection tool for the coaxiality of motor shaft inner holes. This tool solves the problems of long inspection times, expensive equipment, complex operation, and unsuitability for rapid on-site use when using a coordinate measuring machine (CMM) to inspect the coaxiality of motor shaft inner holes. This invention aims to achieve the following technical effects: increase inspection speed, reducing inspection time from several minutes to tens of seconds; reduce equipment costs by using a conventional mechanical structure instead of a high-precision CMM; simplify the operation process for easy mastery by on-site personnel; and improve inspection flexibility to adapt to motor shafts of different sizes.

[0009] The above-mentioned utility model objective is achieved through the following technical solution:

[0010] This utility model provides a quick inspection tool for the coaxiality of the inner hole of a motor shaft, comprising: a main platform having two parallel first guide rail grooves; two support plates, each slidably mounted on the two first guide rail grooves, with the support plates perpendicular to the extension direction of the first guide rail grooves; a second guide rail groove on each support plate, with two sliding blocks slidably mounted in each second guide rail groove; a bearing detachably connected to each sliding block by bolts, with a gap between the two bearings on the same support plate for placing the motor shaft, the outer wall surface of the bearing being tangent to the outer wall surface of the motor shaft; and two sliding platforms, respectively disposed at both ends of one of the first guide rail grooves, each sliding platform having a detachably fixed mounting block, and each mounting block having a dial indicator, the measuring head of which is used to extend into the inner holes at both ends of the motor shaft to measure the runout value.

[0011] According to one embodiment of the present invention, both the first guide rail groove and the second guide rail groove are T-shaped grooves, and the bottom of the bearing plate is provided with a first slider that matches the first guide rail groove. The first guide rail groove is a linear guide rail structure.

[0012] According to one embodiment of the present invention, the bottom of the sliding block is provided with a second slider that matches the second guide rail groove, and the second guide rail groove is a linear guide rail structure.

[0013] According to one embodiment of the present invention, the bearing is a rolling bearing, including a deep groove ball bearing, a self-aligning ball bearing, or a tapered roller bearing. The present invention also provides one such bearing.

[0014] According to one embodiment of the present invention, the dial indicator is fixed on the mounting block by an L-shaped bracket.

[0015] According to one embodiment of the present invention, the main platform is made of cast iron, aluminum alloy or carbon steel, the surface is treated with rust prevention, and it is equipped with leveling feet.

[0016] According to one embodiment of the present invention, the sliding platform can slide within the first guide rail groove and be locked in position by a locking bolt.

[0017] According to one embodiment of the present invention, the height of the mounting block is adjustable, including adjustment by thread or shim.

[0018] According to one embodiment of the present invention, the dial indicator is a mechanical dial indicator or a digital dial indicator, with a measurement accuracy of not less than 0.001 mm.

[0019] According to one embodiment of the present invention, an auxiliary rotating mechanism is also included, which includes a handle or a motor drive wheel for driving the motor shaft to rotate.

[0020] According to one embodiment of this utility model, the main platform also integrates a data acquisition system. The data acquisition system includes a sensor interface, an analog-to-digital converter, and a microprocessor, used to acquire measurement data from the dial indicator in real time and transmit it wirelessly or via wired connection to an external display device or computer. The data acquisition system further includes a data storage module and data analysis software, capable of automatically calculating coaxiality error, generating inspection reports, and recording historical data, facilitating quality traceability and statistical analysis.

[0021] According to one embodiment of this utility model, the surface of the bearing is coated with a wear-resistant coating, such as polytetrafluoroethylene or diamond-like carbon film, to reduce the coefficient of friction and wear, and extend its service life. The thickness of the wear-resistant coating is 5-20 μm, and the coefficient of friction is less than 0.1, ensuring smooth rotation of the motor shaft without scratches.

[0022] According to one embodiment of this utility model, a shock-absorbing mechanism, including a rubber pad or an air cushion, is provided below the main platform to isolate ground vibrations and improve measurement stability. The natural frequency of the shock-absorbing mechanism is below 10Hz, which can effectively attenuate vibration interference from common processing environments.

[0023] According to one embodiment of this utility model, the measuring head of the dial indicator is a replaceable design, including a spherical, conical, or flat measuring head to adapt to inner holes of different shapes and inner diameters. The measuring head is made of cemented carbide or ceramic material with a hardness of not less than HRC60 to ensure wear resistance and measurement accuracy.

[0024] According to one embodiment of the present invention, the gauge further includes an environmental compensation module, comprising a temperature sensor and a humidity sensor, for monitoring environmental conditions and compensating for measurement results in real time, thereby reducing the impact of temperature drift and humidity drift on accuracy.

[0025] According to one embodiment of this utility model, a precision linear bearing is provided between the sliding platform and the first guide rail groove to ensure smooth and gapless sliding. The repeatability of the precision linear bearing is not less than 0.005mm, ensuring the accurate positioning of the dial indicator measuring head.

[0026] According to one embodiment of the present invention, the inspection tool further includes a safety protection device, including a limit switch and a protective cover, to prevent the motor shaft from falling off during rotation or the operator from accidentally touching the moving parts.

[0027] According to one embodiment of this utility model, the main platform is made of a low coefficient of thermal expansion alloy, such as Invar alloy or silicon-aluminum alloy, with a coefficient of thermal expansion of less than 2 × 10⁻⁶. -6 / ℃, ensuring platform dimensional stability under varying ambient temperatures.

[0028] According to one embodiment of this utility model, the inspection tool can be connected to the factory's MES (Manufacturing Execution System) or QMS (Quality Management System) via the Internet or local area network to realize automatic uploading and real-time monitoring of inspection data, supporting smart manufacturing and Industry 4.0 applications.

[0029] The working principle of this invention is based on the runout measurement principle and geometric error analysis theory. When the motor shaft is placed on the bearing support and rotates, the radial runout of the inner hole wall is captured by the dial indicator measuring head. Two dial indicators measure the inner holes at both ends respectively, and the change in their runout values ​​reflects the relative deviation of the axes of the two inner holes. The coaxiality error can be calculated using the following formula:

[0030] Coaxiality error = (Δ1 + Δ2) / 2 + K * L

[0031] Where Δ1 and Δ2 are the maximum runout of the dial indicators at both ends, L is the length of the motor shaft, and K is the axial deviation correction coefficient, typically taken as 0.001-0.005. This invention, by combining dual-point measurement with a mathematical model, eliminates the influence of shaft bending and installation errors on the measurement results, thus improving the accuracy of the evaluation.

[0032] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects:

[0033] This utility model discloses a rapid inspection tool for the coaxiality of the inner hole of a motor shaft, which can improve inspection speed: by using bearing support and direct measurement with a dial indicator, the inspection time is shortened from tens of minutes on a coordinate measuring machine to within a few minutes, significantly improving production efficiency. It also reduces equipment costs: using a conventional mechanical structure and standard measuring elements, the cost is far lower than that of a coordinate measuring machine, making it suitable for small and medium-sized enterprises. Operation is simple: the simple structure requires no professional training, and on-site personnel can quickly master the operation process. It is highly adaptable: through guide rail grooves and adjustable mounting blocks, it can adapt to motor shafts of different lengths and diameters. Precision is reliable: based on high-precision bearing support and dial indicator measurement, the runout value measurement accuracy is high, effectively assessing coaxiality. On-site adjustment is convenient: the inspection results can be fed back instantly, facilitating the adjustment of processing parameters and shortening waiting time. It alleviates the bottleneck of coordinate measuring machines: reducing reliance on coordinate measuring machines, alleviating inspection bottlenecks, and improving equipment utilization. Maintenance is convenient: standardized components make replacement easy after damage, resulting in low maintenance costs.

[0034] This utility model also has the following features:

[0035] Multi-degree-of-freedom adjustable support structure: Through the combination of double guide rail grooves and sliding blocks, the length, diameter and support position of the motor shaft can be flexibly adjusted, which is highly adaptable.

[0036] High-precision measurement system: The system uses a dial indicator to directly measure the runout of the inner hole, and combines data acquisition and environmental compensation to ensure measurement accuracy and reliability.

[0037] Integration and intelligence: Through data acquisition, network communication and automated control, the detection process has been digitized and made intelligent, improving overall efficiency.

[0038] Material and process optimization: The use of wear-resistant coatings, low thermal expansion materials, and high-precision machining processes ensures the long-term stability and durability of the inspection tool.

[0039] Data integration and traceability: Through the data acquisition system, all test data are automatically recorded and stored, supporting quality traceability and statistical analysis, and meeting the requirements of quality management systems such as ISO9001.

[0040] Environmental adaptability: Through vibration reduction and environmental compensation modules, the fixture can work stably in common processing site environments, unaffected by changes in vibration, temperature and humidity.

[0041] Safety and Reliability: With safety protection devices and wear-resistant design, the inspection tool is safe, reliable and has a long service life during use.

[0042] Smart manufacturing compatibility: By integrating with MES / QMS systems, this utility model supports Industry 4.0 and smart manufacturing models, realizing the automation and informatization of the inspection process. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0044] Reference numerals: 1. Main platform; 11. First guide rail groove; 2. Bearing plate; 21. Second guide rail groove; 22. Sliding block; 23. Bolt; 3. Bearing; 4. Sliding platform; 41. Mounting block; 42. L-shaped bracket; 5. Dial indicator; 51. Measuring head; 6. Motor shaft; 61. Inner hole. Detailed Implementation

[0045] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0046] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0048] Reference Figure 1 This utility model discloses a quick inspection tool for the coaxiality of the inner hole of a motor shaft, comprising: a main platform 1, on which two parallel first guide rail grooves 11 are formed; two support plates 2, which are slidably disposed on the two first guide rail grooves 11 respectively, and the support plates 2 are perpendicular to the extension direction of the first guide rail grooves 11; each support plate 2 is provided with a second guide rail groove 21, and two sliding blocks 22 are slidably disposed in each second guide rail groove 21; each sliding block 22 is detachably connected to a bearing 3 by bolts 23, and a gap is formed between the two bearings 3 on the same support plate 2 for placing the motor shaft 6, and the outer wall surface of the bearing 3 is tangent to the outer wall surface of the motor shaft 6; two sliding platforms 4, which are respectively disposed at both ends of one of the first guide rail grooves 11, each sliding platform 4 is detachably fixed with a mounting block 41, and each mounting block 41 is provided with a dial indicator 5, the measuring head 51 of the dial indicator 5 being used to extend into the inner holes 61 at both ends of the motor shaft 6 to measure the runout value.

[0049] Both the first guide rail groove 11 and the second guide rail groove 21 are T-shaped grooves. The bottom of the bearing plate 2 is provided with a first slider that matches the first guide rail groove 11. The first guide rail groove 11 is a linear guide rail structure. The bottom of the sliding block 22 is provided with a second slider that matches the second guide rail groove 21. The second guide rail groove 21 is a linear guide rail structure.

[0050] The bearing 3 is a rolling bearing 3, including a deep groove ball bearing 3, a self-aligning ball bearing 3, or a tapered roller bearing 3. The present invention also provides one such bearing. The dial indicator 5 is fixed to the mounting block 41 by an L-shaped bracket 42.

[0051] The main platform 1 is made of cast iron, aluminum alloy, or carbon steel, with a rust-proof surface and leveling feet. The sliding platform 4 can slide within the first guide rail groove 11 and is locked in position by locking bolts 23. The height of the mounting block 41 is adjustable, including by thread adjustment or shim adjustment. The dial indicator 5 is a mechanical dial indicator 5 or a digital dial indicator 5, with a measurement accuracy of not less than 0.001 mm. An auxiliary rotating mechanism is also included, which includes a handle or motor drive wheel for driving the motor shaft 6 to rotate.

[0052] The main platform 1 is a rectangular plate structure made of cast iron or aluminum alloy, possessing sufficient rigidity and stability. Two parallel first guide rail grooves 11 are formed on the main platform 1. These first guide rail grooves 11 are T-shaped grooves used to guide the sliding of the support plate 2. The length of the two first guide rail grooves 11 can be adjusted according to the length of the motor shaft 6, typically ranging from 300mm to 1000mm.

[0053] Two support plates 2 are slidably disposed within the first guide rail groove 11. Each support plate 2 is a long strip made of steel, and its bottom has a first slider that matches the first guide rail groove 11, allowing the support plate 2 to slide within the first guide rail groove 11 and be locked in the desired position by locking bolts 23. The support plate 2 is perpendicular to the extending direction of the first guide rail groove 11.

[0054] Each support plate 2 has a second guide groove 21, which is parallel to the length of the support plate 2. Two sliding blocks 22 are slidably disposed within each second guide groove 21. The sliding blocks 22 are rectangular blocks made of steel, and their bottoms have second sliders that match the second guide groove 21, allowing the sliding blocks 22 to slide and lock within the second guide groove 21. Each sliding block 22 is detachably connected to a bearing 3 via bolts 23. The bearing 3 is a rolling bearing 3, such as a deep groove ball bearing 3, with a smooth outer ring surface for contact with the outer wall of the motor shaft 6.

[0055] A gap is formed between two bearings 3 on the same support plate 2 to accommodate the motor shaft 6. The motor shaft 6 is placed horizontally on the four bearings 3, with the outer wall of the bearing 3 tangent to the outer wall of the motor shaft 6, allowing the motor shaft 6 to rotate easily, and the bearings 3 to rotate synchronously with the motor shaft 6, reducing friction.

[0056] Sliding platforms 4 are respectively provided at both ends of one of the first guide rail grooves 11. The sliding platform 4 is a plate-shaped structure that can slide within the first guide rail groove 11. A mounting block 41 is detachably fixed to each sliding platform 4 by bolts 23, and a dial indicator 5 is provided on the mounting block 41. The dial indicator 5 is a mechanical or digital dial indicator, and its measuring head 51 extends into the inner holes 61 at both ends of the motor shaft 6. The dial indicator 5 is fixed to the mounting block 41 by an L-shaped bracket 42.

[0057] During operation, place the motor shaft 6 on the four bearings 3, and adjust the positions of the support plate 2 and the sliding block 22 to ensure that the bearings 3 evenly support the motor shaft 6. Then, adjust the position of the sliding platform 4 so that the measuring head 51 of the dial indicator 5 extends into the inner hole 61 and contacts the inner wall. Slowly rotate the motor shaft 6 and observe the runout value of the dial indicator 5. Record the maximum and minimum readings of the two dial indicators 5, calculate the runout, and thus assess the coaxiality.

[0058] This invention also includes a data acquisition system, which comprises a sensor interface, an analog-to-digital converter, a microprocessor, and a wireless transmission module. The sensor interface is connected to a dial indicator 5 to receive analog measurement signals; the analog-to-digital converter converts the analog signals into digital signals; the microprocessor processes the digital signals and calculates the coaxiality error; the wireless transmission module sends the processed data to an external device, such as a computer or smartphone. The data acquisition system may also include an LCD display screen for real-time display of measurement results.

[0059] The measurement principle of this invention is based on geometric error analysis. When the motor shaft 6 rotates, the axial deviation of the inner hole 61 causes radial runout of the measuring head 51 of the dial indicator 5. Let the runout values ​​of the two dial indicators be Δ1 and Δ2 respectively, and the length of the motor shaft be L, then the coaxiality error δ can be expressed as:

[0060] δ=(Δ1+Δ2) / 2+K*L;

[0061] Where K is a correction factor, typically ranging from 0.001 to 0.005, used to compensate for axial deviation. This model eliminates the influence of shaft bending through two-point measurement, improving the accuracy of the assessment.

[0062] The environmental compensation module of this invention includes a temperature sensor and a humidity sensor, which monitor the ambient temperature and humidity respectively. The microprocessor performs real-time compensation on the measurement results based on the sensor data, and the compensation formula is as follows:

[0063] Compensation value = α*(T-T0) + β*(H-H0);

[0064] Where α and β are the coefficients of thermal expansion and hygroscopic expansion of the material, and T0 and H0 are the standard temperature and humidity. Environmental compensation reduces the impact of temperature drift and humidity drift on measurement accuracy.

[0065] The shock absorption mechanism of this invention includes a rubber pad and an air cushion, which are installed at the bottom of the main platform 1. The rubber pad provides basic shock absorption, while the air cushion can be adjusted to adapt to different weights and vibration conditions by adjusting the air pressure. The natural frequency of the shock absorption mechanism is designed to be 5Hz, which can effectively isolate ground vibration and ensure measurement stability.

[0066] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are for illustrative purposes only and do not constitute a limitation on the scope of protection of the present invention.

[0067] Example 1:

[0068] like Figure 1 As shown, a quick inspection tool for the coaxiality of the inner hole of a motor shaft includes a main platform 1, a bearing plate 2, a bearing 3, a sliding platform 4, and a dial indicator 5.

[0069] The main platform 1 is made of HT250 cast iron, with dimensions of 1000mm × 500mm × 50mm. Its surface is ground, with a flatness error not exceeding 0.02mm. The main platform 1 has two parallel first guide rail grooves 11, each a T-shaped groove, 20mm wide and 15mm deep, with a center distance of 400mm between the two grooves. The bottom of the main platform 1 has four leveling feet for adjusting its level.

[0070] Two support plates 2 are slidably disposed within the first guide rail groove 11. The support plates 2 are made of 45# steel and have dimensions of 200mm×80mm×30mm. A first slider matching the first guide rail groove 11 is provided at the bottom of each plate. The surface of the slider is coated with grease to reduce friction. The support plates 2 are locked within the first guide rail groove 11 by hand-tightening bolts 23.

[0071] Each support plate 2 has a second guide rail groove 21, which is a linear guide rail structure with a width of 15mm and a depth of 10mm. Two sliding blocks 22 are slidably disposed within each second guide rail groove 21. The sliding blocks 22 are made of 40Cr steel, with dimensions of 50mm × 50mm × 40mm, and have a second slider at their bottom that matches the second guide rail groove 21. Each sliding block 22 is detachably connected to a bearing 3 via an M8 bolt 23. The bearing 3 is a 6204 deep groove ball bearing 3 with an outer diameter of 47mm, an inner diameter of 20mm, and a width of 14mm.

[0072] A gap of 50mm is formed between two bearings 3 on the same support plate 2 to accommodate the motor shaft 6. The motor shaft 6 is placed horizontally on the four bearings 3, with the outer wall of the bearing 3 tangent to the outer wall of the motor shaft 6. The motor shaft 6 has a diameter of 40mm and a length of 600mm.

[0073] Sliding platforms 4 are respectively provided at both ends of one of the first guide rail grooves 11. The sliding platforms 4 are made of aluminum alloy and have dimensions of 100mm × 60mm × 20mm, and can slide within the first guide rail groove 11. Each sliding platform 4 is detachably fixed with a mounting block 41 by bolts 23, and a dial indicator 5 is provided on the mounting block 41. The dial indicator 5 is a Mitutoyo digital dial indicator 5, with a measuring range of 0-10mm and an accuracy of 0.001mm. The dial indicator 5 is fixed to the mounting block 41 by an L-shaped bracket 42, and the measuring head 51 extends into the inner holes 61 at both ends of the motor shaft 6, the inner holes 61 having a diameter of 25mm.

[0074] During operation, place the motor shaft 6 on the four bearings 3, and adjust the positions of the support plate 2 and the sliding block 22 to ensure that the bearings 3 evenly support the motor shaft 6. Then, adjust the position of the sliding platform 4 so that the measuring head 51 of the dial indicator 5 extends into the inner hole 61 and contacts the inner wall. Slowly rotate the motor shaft 6 and observe the runout value of the dial indicator 5. Record the maximum and minimum readings of the two dial indicators 5 and calculate the runout. The coaxiality error is half of the runout.

[0075] In this embodiment, a data acquisition system is also integrated. The sensor interface of the data acquisition system is connected to the dial indicator 5. The analog-to-digital converter uses a 16-bit ADC with a sampling rate of 1kHz. The microprocessor 73 is an ARM Cortex-M4, running a custom algorithm to calculate coaxiality error. The wireless transmission module is a Wi-Fi module, sending data to the workshop computer in real time. Simultaneously, an environmental compensation module monitors environmental conditions; the temperature sensor has an accuracy of ±0.1℃, and the humidity sensor has an accuracy of ±3%RH. The microprocessor corrects the measurement results according to the compensation formula. The rubber pad of the shock absorption mechanism is 10mm thick, and the air pressure of the air cushion is adjustable from 0.1-0.5MPa to ensure platform stability.

[0076] Example 2:

[0077] Based on Embodiment 1, the present invention can also adopt the following variations: the bearing 3 can be replaced with a self-aligning ball bearing 3 or a tapered roller bearing 3 to accommodate motor shafts 6 of different diameters. The dial indicator 5 can be replaced with a laser displacement sensor to achieve non-contact measurement. The main platform 1 can be made of carbon steel with a chrome-plated surface for rust prevention.

[0078] The height of mounting block 41 can be adjusted via a thread, for example, by setting an adjusting screw at the bottom of mounting block 41 for fine-tuning the height of measuring head 51. An auxiliary rotating mechanism, including a handle or motor drive wheel, can be added to drive the motor shaft 6 to rotate, improving ease of operation.

[0079] In this embodiment, the data acquisition system is upgraded to an industrial IoT terminal, supporting 4G / 5G communication and capable of directly uploading data to a cloud platform. The cloud platform provides big data analytics functions, such as trend prediction, anomaly detection, and optimization suggestions. Meanwhile, safety protection devices include limit switches and a transparent protective cover. The limit switches are installed at the end of the travel of the sliding platform 4 to prevent overtravel; the protective cover covers the rotating parts to prevent operator contact.

[0080] Example 3:

[0081] To further improve detection accuracy, this utility model may also include the following features:

[0082] A level is installed on the main platform 1 for real-time monitoring of the platform's levelness. The dial indicator 5 uses a wireless transmission model, directly transmitting data to a computer or mobile device for automatic recording and analysis. The bearing 3 is coated with a wear-resistant coating, such as PTFE, to extend its service life.

[0083] In this embodiment, the material of the main platform 1 is replaced with Invar alloy, which has a coefficient of thermal expansion of 1.2 × 10⁻⁶. -6 / ℃, ensuring that the platform size change is less than 0.01mm under ambient temperatures of 10-40℃. The measuring head 51 of the dial indicator 5 has been replaced with a carbide spherical head, 3mm in diameter, with a hardness of HRC65, suitable for deep hole measurement. The data acquisition system has been enhanced with a data storage module with a capacity of 32GB, capable of storing over 100,000 sets of test data, supporting USB export and remote access.

[0084] Example 4:

[0085] This invention can also be used to detect the coaxiality of the inner holes of other shaft parts, such as gearbox shafts and hydraulic cylinder shafts. Taking a gearbox shaft as an example, the shaft is 800mm long, with an outer diameter of 60mm and an inner diameter of 30mm. By adjusting the position of the bearing plate 2 and the spacing of the sliding blocks 22, this invention can be easily adapted. The dial indicator 5 is replaced with a large-range model (0-25mm), and the measuring head 51 adopts a tapered design for easy access to the tapered inner hole. The data acquisition system has a customized software interface that supports parameter settings and report generation for various shaft parts.

[0086] Example 5:

[0087] In high-speed testing scenarios, this invention integrates a servo motor-driven auxiliary rotation mechanism with adjustable rotation speed (1-100 rpm) to achieve automated measurement. Simultaneously, the data acquisition system incorporates a real-time filtering algorithm to eliminate vibration noise and ensure data accuracy. The vibration damping mechanism is upgraded to an active air-bearing vibration isolation system with a natural frequency below 2Hz, suitable for high-precision laboratory environments.

[0088] Working principle:

[0089] This invention evaluates coaxiality based on the principle of runout measurement. The motor shaft 6 is placed on four bearings 3, which serve as supporting references to ensure stability during shaft rotation. A dial indicator 5 with its measuring head 51 extends into the inner hole 61. As the shaft rotates, the runout of the inner hole 61 wall is recorded by the dial indicator 5. Two dial indicators 5 measure the runout at both ends of the inner hole 61, and the change in runout value reflects the deviation of the axes of the two inner holes 61. By calculating the maximum and minimum runout values, the coaxiality error can be determined.

[0090] More specifically, the workflow of this utility model includes the following steps: Initialization: Adjust the main platform 1 to be level, and start the data acquisition system and environmental compensation module. Workpiece Installation: Place the motor shaft 6 on the bearing 3 and adjust the support position to achieve balance. Measuring Head Positioning: Slide the sliding platform 4 so that the measuring head 51 of the dial indicator 5 extends into the inner hole 61 and is pre-pressed by 0.1-0.3 mm. Rotation Measurement: Manually or automatically rotate the motor shaft 6, and the data acquisition system records the runout data. Data Processing: The microprocessor calculates the coaxiality error and applies environmental compensation. Result Output: The data is displayed on the local screen or sent to an external system, generating a test report. Maintenance and Calibration: Regularly clean the guide rails and bearings, check the dial indicator accuracy, and verify the platform level.

[0091] Test data:

[0092] To verify the practicality of this invention, the present inspection tool was used to inspect the shaft 6 of a certain model of motor, and the results were compared with those obtained by a coordinate measuring machine. The results are shown in the table below:

[0093]

[0094] Test results show that the detection results of this utility model are consistent with those of the coordinate measuring machine, and the error is within an acceptable range, meeting the requirements for on-site testing.

[0095] To further verify the long-term stability and environmental adaptability of this invention, accelerated life testing and environmental testing were conducted. The accelerated life test included 1000 hours of continuous operation and testing of 10,000 motor shafts. The results showed that the coaxiality error measurement deviation was less than 0.002 mm, and the wear of bearing 3 was less than 0.01 mm. The environmental test included measurements under conditions of temperature 10-40℃ and humidity 30-80%RH. The results showed that the environmental compensation module effectively controlled temperature drift and humidity drift within 0.001 mm.

[0096] Economic Benefit Analysis: The manufacturing cost of a single unit of this utility model is approximately 1 / 10 of that of a coordinate measuring machine, while improving inspection efficiency by 80% and reducing downtime by 70%. Based on an annual production of 100,000 motor shafts, it can save approximately 500,000 yuan in inspection costs per year, with a payback period of less than 6 months.

[0097] The gauge of this utility model requires regular maintenance and calibration, including: cleaning the guide rail groove and bearing 3 to prevent dust from affecting the sliding; checking the accuracy of the dial indicator 5 and sending it for inspection regularly; verifying the levelness of the platform and adjusting the leveling feet; and checking the tightness of the bolts 23 to prevent loosening.

[0098] This invention has been applied to the processing site of a motor manufacturing company, improving inspection efficiency by approximately 80% and reducing downtime by 70%, receiving positive feedback from users. This invention provides a rapid inspection tool for the coaxiality of motor shaft inner holes. Through innovative structural design, it achieves rapid, simple, and low-cost coaxiality inspection. This tool has significant technical advantages and economic benefits, making it suitable for widespread use in the machinery manufacturing field.

[0099] This invention can also be extended to other fields, such as automobiles, aerospace, and precision instruments, for detecting the coaxiality of the inner holes of various shaft parts. In the future, adaptive detection and predictive maintenance can be achieved through artificial intelligence technology, further enhancing the level of intelligence.

[0100] The implementation principle of this utility model is as follows: This utility model discloses a quick inspection tool for the coaxiality of the inner hole of a motor shaft, including a main platform 1. The main platform 1 has two parallel first guide rail grooves 11. Two bearing plates 2 are slidably arranged within the first guide rail grooves 11, with the bearing plates 2 perpendicular to the extending direction of the first guide rail grooves 11. Each bearing plate 2 has a second guide rail groove 21, with two mounting blocks 41 slidably arranged within the second guide rail groove 21. Each mounting block 41 is detachably connected to a bearing 3 by bolts 23. A gap is formed between the two bearings 3 on the same bearing plate 2 for placing the motor shaft 6. The outer wall surface of the bearing 3 is tangent to the outer wall surface of the motor shaft 6. Sliding platforms 4 are provided at both ends of one of the first guide rail grooves 11. Mounting blocks 41 are detachably fixed on the sliding platforms 4. A dial indicator 5 is installed on the mounting blocks 41, and the measuring head 51 of the dial indicator 5 extends into the inner holes 61 at both ends of the motor shaft 6 to measure the runout value. By comparing the values ​​of the two dial indicators 5, the coaxiality of the inner holes 61 of the motor shaft 6 can be quickly assessed. This invention has a simple structure and is easy to operate, making it suitable for rapid on-site testing.

[0101] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A quick inspection tool for the coaxiality of the inner hole of a motor shaft, characterized in that, include: The main platform (1) has two parallel first guide rail grooves (11) on it; Two support plates (2) are slidably disposed on two first guide rail grooves (11), and the support plates (2) are perpendicular to the extension direction of the first guide rail grooves (11); Each of the bearing plates (2) is provided with a second guide rail groove (21), and two sliding blocks (22) are slidably arranged in each second guide rail groove (21); Each of the sliding blocks (22) is detachably connected to a bearing (3) by bolts (23). A gap is formed between two bearings (3) on the same bearing plate (2) for placing the motor shaft (6). The outer wall surface of the bearing (3) is tangent to the outer wall surface of the motor shaft (6). Two sliding platforms (4) are respectively set at both ends of one of the first guide rail grooves (11). Each sliding platform (4) is detachably fixed with a mounting block (41). Each mounting block (41) is equipped with a dial indicator (5). The measuring head (51) of the dial indicator (5) is used to extend into the inner holes (61) at both ends of the motor shaft (6) to measure the runout value.

2. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, Both the first guide rail groove (11) and the second guide rail groove (21) are T-shaped grooves. The bottom of the bearing plate (2) is provided with a first slider that matches the first guide rail groove (11). The first guide rail groove (11) is a linear guide rail structure.

3. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The bottom of the sliding block (22) is provided with a second slider that matches the second guide groove (21), and the second guide groove (21) is a linear guide structure.

4. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The bearing (3) is a rolling bearing, including one of a deep groove ball bearing, a self-aligning ball bearing, or a tapered roller bearing.

5. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The dial indicator (5) is fixed to the mounting block (41) by an L-shaped bracket (42).

6. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The main platform (1) is made of cast iron, aluminum alloy or carbon steel, with rust prevention treatment on the surface and is equipped with leveling feet (12).

7. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The sliding platform (4) can slide within the first guide rail groove (11) and be locked in position by locking bolts.

8. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The height of the mounting block (41) is adjustable, including by thread adjustment or shim adjustment.

9. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, The dial indicator (5) is a mechanical dial indicator or a digital dial indicator, with a measurement accuracy of not less than 0.001 mm.

10. The quick inspection tool for the coaxiality of the inner hole of the motor shaft according to claim 1, characterized in that, It also includes an auxiliary rotation mechanism, which includes a handle or a motor drive wheel for driving the motor shaft (6) to rotate.

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