Gear detection system based on circular grating

Abstract

The invention discloses a gear detection system based on a circular grating. A torque motor is installed in a rear box body, a motor shaft is rotatably installed in the rear box body, a supporting sleeve is fixed to the periphery of the motor shaft, and a rotor part is fixed to the periphery of the supporting sleeve to be matched with a stator part; the grating mounting shaft is rotationally mounted at the two ends of the front box body double-end spline shaft, and is in spline fit with the grating mounting shaft and the motor shaft in a clearance fit manner in the length direction; according to the gear detection system based on the circular grating, when the torque motor is normally started or operates at large torque / high rotating speed, most of vibration is absorbed and transmitted by the supporting sleeve, the motor shaft and the grating mounting shaft are connected through the double-end spline shaft, and when vibration is transmitted between the motor shaft and the grating mounting shaft, the motor shaft and the grating mounting shaft are connected through the double-end spline shaft. Due to the fact that the two ends of the double-end spline shaft are in clearance fit, partial vibration and heat transfer are blocked. The operation state and the stable state at the position of the grating mounting shaft are ensured to be more stable, and finally the test precision is also improved.

Description

Technical Field

[0001] The present invention relates to the field of gear detection structure equipment, and particularly to a gear detection system based on a circular grating. Background Art

[0002] The main shaft drive system plays a crucial role in gear detection equipment. It not only includes the working main shaft of the equipment and its transmission components, but also covers a torque measurement device and a gear measurement device. In the market, the commonly adopted method is direct drive by a motor. The main purpose of this drive method is to ensure that the gear to be detected can reach a predetermined rotational speed, torque, and rotational direction. To further ensure the measurement accuracy, a circular grating (encoder) used for measurement is usually installed at the front end of the main shaft, close to the gear to be measured.

[0003] The above integrated main shaft design also brings some problems. The main defect is that factors such as the vibration and heat energy of the motor are directly transmitted to the gear to be measured, which may affect the detection. Especially during large torque tests, this influence is particularly obvious, making it difficult to distinguish whether the vibration source comes from the gear itself or the motor in the measurement results. This makes it difficult to effectively process through filtering technology, thereby affecting the accuracy of the test data. In addition, the maintenance cost of this structure is relatively high, which brings additional inconvenience and economic burden during the later maintenance, upkeep, and replacement of consumables such as bearings. At the same time, traditional gear inspection equipment generally pastes strain gauges for measuring torque on the front part of the main shaft. However, the diameter of the main shaft that can transmit high torque is relatively large, which will result in a very small strain and low measurement accuracy, and cannot truly reflect the strain received by the gear. Summary of the Invention

[0004] The main purpose of the present invention is to provide a gear detection system based on a circular grating, aiming to solve the problem that the vibration and heat of the motor are easily transmitted to the output end of the rotating shaft and affect the work.

[0005] To achieve the above purpose, the present invention provides a gear detection system based on a circular grating, including: A rear box body; A torque motor installed in the rear box body. The torque motor includes a stator part, a motor shaft, a support sleeve, and a rotor part. The stator part is circumferentially arranged on the inner wall of the rear box body. The motor shaft is rotatably installed in the rear box body. The support sleeve is fixed on the outer periphery of the motor shaft. The rotor part is fixed on the outer periphery of the support sleeve and forms a cooperation with the stator part; A front box body connected to the rear box body; A grating installation shaft rotatably installed in the front box body. One end of the grating installation shaft far from the motor shaft is connected with a circular grating module; The double-headed spline shaft is in spline fit with the grating mounting shaft and the motor shaft at both ends respectively, and is in clearance fit in the length direction. The strain gauge is installed on the peripheral wall of the double-headed spline shaft, and the strain gauge detects and sends a strain sensing signal.

[0006] Further, a gear measuring module is connected to one end of the grating mounting shaft away from the motor shaft.

[0007] Further, elastic rings are clamped between the two ends of the double-headed spline shaft in the length direction and the motor shaft and the grating mounting shaft in the length direction.

[0008] Further, the spline fit formed between the double-headed spline shaft and the grating mounting shaft and the motor shaft is in clearance fit in the circumferential direction.

[0009] Further, a plurality of first spline teeth are provided on the outer wall of one end of the double-headed spline shaft corresponding to the motor shaft, and a plurality of second spline teeth corresponding to the plurality of first spline teeth are provided on the inner wall of the motor shaft. A buffer strip with an L-shaped cross section is provided between the corresponding first spline teeth and the second spline teeth, and the buffer strip is clamped in the thickness direction and the height direction of the first spline teeth and the second spline teeth.

[0010] Further, the front box body is slidably arranged on the rear box body in the length direction.

[0011] Further, an annular groove is provided in the middle of the double-headed spline shaft in the length direction, and the strain gauge is arranged at the groove position.

[0012] Further, the support sleeve is made of a flexible material, and a tightening sleeve for expanding the outer diameter of the support sleeve is provided on the inner circumference corresponding to the support sleeve.

[0013] Further, both the grating mounting shaft and the motor shaft are of a cylindrical hollow structure.

[0014] Further, a rotational speed measuring module and a torque measuring module are provided at the outer end corresponding to the motor shaft.

[0015] In the gear detection system based on a circular grating provided by the present invention, when the torque motor is normally started or operates at a large torque / high speed, most of the vibrations generated will be absorbed and transmitted by the support sleeve. The motor shaft and the grating mounting shaft are connected through the double-headed spline shaft. When the vibration is transmitted between the motor shaft and the grating mounting shaft, since the double-headed spline shaft is in clearance fit at both ends, part of the vibration and heat transmission will be blocked. The operating state and the stable state at the position of the grating mounting shaft are both more stable, and finally the test accuracy is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic cross-sectional view of the gear detection system based on a circular grating according to the first embodiment of the present invention; Figure 2 is a schematic cross-sectional view of the gear detection system based on a circular grating according to the second embodiment of the present invention; Figure 3 is an exploded assembly view of the motor shaft, grating mounting shaft, and double-headed spline shaft in the gear detection system based on a circular grating according to the second embodiment of the present invention; Figure 4 is an exploded assembly view (cross-sectional view) of the motor shaft, grating mounting shaft, and double-headed spline shaft in the gear detection system based on a circular grating according to the second embodiment of the present invention; Figure 5 is an assembly drawing of the motor shaft, grating mounting shaft, and double-headed spline shaft in the gear detection system based on a circular grating according to the third embodiment of the present invention (the first perspective); Figure 6 is Figure 5 a partial enlargement in; Figure 7 is an assembly drawing of the motor shaft, grating mounting shaft, and double-headed spline shaft in the gear detection system based on a circular grating according to the third embodiment of the present invention (the second perspective); Figure 8 is Figure 7 a partial enlargement in.

[0017] The realization of the object, functional features, and advantages of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific Embodiments

[0018] It should be understood that the specific embodiments described herein are merely used to explain the present invention and are not used to limit the present invention.

[0019] Those skilled in the art of the present technology can understand that unless specifically stated otherwise, the singular forms "a", "an", "the", "above-mentioned", and "this" used herein may also include the plural forms. It should be further understood that the term "including" used in the specification of the present invention means the presence of the described features, integers, steps, operations, elements, units, modules, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, units, modules, components, and / or their groups. It should be understood that when we say that an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any unit and all combinations of one or more related listed items.

[0020] Those skilled in the art can understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as herein.

[0021] Referring to Figures 1 to 8 , in an embodiment of the present invention, a gear detection system based on a circular grating includes: Rear box body 100; Torque motor 200, installed inside the rear box body 100. The torque motor 200 includes a stator portion 210, a motor shaft 220, a support sleeve 230, and a rotor portion 240. The stator portion 210 is circumferentially arranged on the inner wall of the rear box body 100. The motor shaft 220 is rotatably installed in the rear box body 100. The support sleeve 230 is fixed to the outer periphery of the motor shaft 220. The rotor portion 240 is fixed to the outer periphery of the support sleeve 230 and forms a cooperation with the stator portion 210; Front box body 300, connected to the rear box body 100; Grating installation shaft 400, rotatably installed in the front box body 300. One end of the grating installation shaft 400 away from the motor shaft 220 is connected with a circular grating module; Double-headed spline shaft 500, the two ends of which are respectively in spline fit with the grating installation shaft 400 and the motor shaft 220 and are in clearance fit in the length direction; Strain gauge 600, installed on the peripheral wall of the double-headed spline shaft 500. The strain gauge 600 detects and sends a strain sensing signal.

[0022] In the prior art, the main defect in the spindle design is that factors such as the vibration and heat energy of the motor are directly transmitted to the gear to be measured; especially when performing a large torque test, this influence is particularly obvious, resulting in the difficulty of distinguishing whether the vibration source comes from the gear itself or the motor in the measurement result.

[0023] The gear detection system based on a circular grating provided by the present invention includes a rear box body 100 as the main structural basis.

[0024] The torque motor 200 is installed inside the rear box body 100 to provide power output. The torque motor 200 includes a stator part 210, a motor shaft 220, a support sleeve 230, and a rotor part 240. The stator part 210 is circumferentially arranged on the inner wall of the rear box body 100, and the motor shaft 220 is rotatably installed in the rear box body 100. The support sleeve 230 is fixed to the outer periphery of the motor shaft 220, and the rotor part 240 is fixed to the outer periphery of the support sleeve 230 to cooperate with the stator part 210. The rotation of the motor shaft 220 is realized by bearings at corresponding positions, and specific details are not limited. The support sleeve 230 can provide a buffering effect, thereby providing a basis for blocking the transmission of vibration and heat. The motor shaft 220 can be supported on the rear box body 100 through high-precision angular contact bearings. The support sleeve 230 can adopt a structure with a hollow middle part to effectively space the vibration brought by the rotor part 240.

[0025] The front box body 300 is connected to the rear box body 100. The front box body 300 can be installed by means such as screws, and the connection method between the rear box body 100 and the front box body 300 can be an end face nut, etc. In some embodiments, through certain structural designs, the front box body 300 can also be slidably arranged on the rear box body 100, providing a basis for working state adjustment and maintenance.

[0026] The grating installation shaft 400 is rotatably installed in the front box body 300, and the rotation of the grating installation shaft 400 is realized by bearings at corresponding positions, and specific details are not limited. One end of the grating installation shaft 400 away from the motor shaft 220 is connected with a circular grating module.

[0027] In this embodiment, through the introduction of the circular grating module, the rotation structure of the grating installation shaft 400 can be accurately monitored. The purpose of the gear detection system based on the circular grating can be to output stable and accurate torque, then the installation of the gear measurement module can perform the action of gear testing. The main spindle box requires torque and grating (angle) measurement, and the closer to the gear to be tested, the more accurate the measurement data.

[0028] Both ends of the double-headed spline shaft 500 are respectively in spline fit with the grating installation shaft 400 and the motor shaft 220 and are in clearance fit in the length direction. Both ends of the double-headed spline shaft 500 form spline fits, so that the rotation of the motor shaft 220 can be transmitted to the grating installation shaft 400. And both ends of the double-headed spline shaft 500 in the length direction are respectively in clearance fit with the grating installation shaft 400 and the motor shaft 220, so that the double-headed spline shaft 500 can achieve a certain degree of slip in the length direction. The characteristics of the above clearance fit can block the transmission of vibration and heat to a certain extent.

[0029] The strain gauge 600 is installed on the peripheral wall of the double-headed spline shaft 500, and the strain gauge 600 detects and sends a strain sensing signal. The power supply of the strain gauge 600 can be obtained on the double-headed spline shaft 500 or from outside the double-headed spline shaft 500 by means of wireless charging. The preferred way for the strain gauge 600 to transmit signals outward is wireless. According to the data stability of the strain gauge 600, the rotational stability characteristics of the double-headed spline shaft 500 can also be calculated and judged. For example, if the test data of the strain gauge 600 shows large fluctuations, it means that there is a problem with the installation of the double-headed spline shaft 500.

[0030] During the installation process: First step, install the rear housing 100; Install the stator part 210 on the rear housing 100. Specifically, an installation plate can be set for the stator part 210. After fixing the stator part 210 to the installation plate, fix the installation plate to the rear housing 100. After correcting the mating position of the stator part 210 and the rear housing 100, conduct a leak-proof test to ensure that the stator part 210 does not leak. Install the front bearing and the front bearing cover of the rear housing 100. Then combine the rotor part 240 with the support sleeve 230, insert the motor shaft 220 into the support sleeve 230, and use the expansion sleeve 250 to expand and tighten to form a correspondence between the rotor part 240 and the stator part 210. Install the rear bearing and the rear bearing cover of the rear housing 100, and then lock the relevant fixing screws in sequence to complete the installation of the rear housing 100 part.

[0031] Second step, double-headed spline shaft; After installing the strain gauge 600 on the double-headed spline shaft 500, form a fit between the double-headed spline shaft 500 and the motor shaft 220.

[0032] Third step, install the front housing 300; Install the grating installation shaft 400 on the front housing 300 through a rotary bearing.

[0033] Fourth step, integration; Push the front housing 300 to one side of the double-headed spline shaft 500 to ensure the normal operation of the transmission chain of the grating installation shaft 400, and finally install the front housing 300 with screws.

[0034] In summary, when the torque motor 200 starts normally or operates at high torque / high speed, most of the vibrations generated will be absorbed and transmitted by the support sleeve 230. The motor shaft 220 and the grating installation shaft 400 are connected through the double-headed spline shaft 500. When the vibration is transmitted between the motor shaft 220 and the grating installation shaft 400, since the double-headed spline shaft 500 has a clearance fit at both ends, it will block the transmission of part of the vibration and heat. Ensure that the operating state and the stable state at the position of the grating installation shaft 400 are both more stable, and finally the test accuracy is also improved.

[0035] In one embodiment, a gear measurement module is connected to one end of the grating mounting shaft 400 away from the motor shaft 220.

[0036] In this embodiment, the headstock requires torque and grating (angle) measurement, and the measurement data is more accurate closer to the gear being tested. Therefore, a circular grating module and a gear measurement module are connected to one end of the grating mounting shaft 400 away from the motor shaft 220. Through the relevant settings of the above double-headed spline shaft 500, the driving and measurement parts are separated, ensuring stable output while guaranteeing the measurement accuracy.

[0037] In one embodiment, temperature sensors are respectively arranged at both ends of the double-headed spline shaft 500 in the length direction. Through the sensing data of the two temperature sensors, it can be determined whether the temperature characteristics of the entire spindle are normal. Moreover, the above temperature test results reflect the temperature characteristics of the motor shaft 220 and the grating mounting shaft 400, further reflecting the temperature isolation effect of the double-headed spline shaft 500. The power supply and data transmission channels of the temperature sensors can share those of the strain gauge 600.

[0038] Refer to Figures 2 to 4 , in one embodiment, an elastic ring 700 is clamped between the two ends of the double-headed spline shaft 500 in the length direction and the motor shaft 220 and the grating mounting shaft 400 in the length direction.

[0039] In this embodiment, the double-headed spline shaft 500 is clamped in the length direction through the elastic ring 700, so that the vibration of the rear housing 100 part and the torque motor 200 part in the length direction will be isolated from the grating mounting shaft 400 to a certain extent. Taking the grating mounting shaft 400 as an example, a stepped structure is provided on the grating mounting shaft 400, and a corresponding stepped structure is also provided on the double-headed spline shaft 500, thus providing a basis for the installation of the elastic ring 700. The elastic ring 700 can be a disc spring or a stack of multiple ring structures.

[0040] Refer to Figures 5 to 8 , in one embodiment, the spline fit formed between the double-headed spline shaft 500 and the grating mounting shaft 400 and the motor shaft 220 is a clearance fit in the circumferential direction.

[0041] In this embodiment, a precise clearance fit is formed through the fitting structure of the double-headed spline shaft 500, making the transmission of the double-headed spline shaft 500 more stable. For the spline fit formed by the double-headed spline shaft 500, if the clearance is too large, vibration or collision may occur, which will have a negative impact on the transmission; when there is no clearance, it is not conducive to installation and instead increases the transmission of vibration and heat.

[0042] Refer to Figures 5 to 8, in one embodiment, a plurality of first spline teeth 510 are provided on the outer wall of one end of the double-headed spline shaft 500 corresponding to the motor shaft 220. A plurality of second spline teeth corresponding to the plurality of first spline teeth 510 are provided on the inner wall of the motor shaft 220 in the circumferential direction. A buffer strip 520 with an L-shaped cross-section is provided between the corresponding first spline teeth 510 and the second spline teeth. The buffer strip 520 is clamped in the thickness direction and the height direction of the first spline teeth 510 and the second spline teeth.

[0043] During the process with a small and accurate angle, there are certain defects in the clearance fit of the above splines. In this embodiment, through the buffer strip 520, while enabling a stable connection to be formed between the double-headed spline shaft 500 and the motor shaft 220, it can also avoid the efficient transmission of vibration and heat brought by rigid connections. The plurality of buffer strips 520 can be of a split structure and individually form a fit with each first spline tooth 510 and second spline tooth pair; connections can be formed between the plurality of buffer strips 520, for example, a circumferential connection can be formed through an annular structure.

[0044] In one embodiment, the front box body 300 is slidably arranged on the rear box body 100 in the length direction.

[0045] In this embodiment, the front box body 300 is arranged to be slidably arranged based on the rear box body 100, so that the difficulty of maintaining the double-headed spline shaft 500 is reduced. Specifically, fixing bolts are provided corresponding to the front box body 300 and the rear box body 100 on the end face. After the fixing bolts are removed, the front box body 300 can complete the sliding action. After the front box body 300 is separated, both the buffer strip 520 and the double-headed spline shaft 500 can be installed and maintained. The sliding arrangement of the front box body 300 facilitates operation and also eliminates the need for alignment.

[0046] In a specific embodiment, the outer diameter of one end of the double-headed spline shaft 500 near the motor shaft 220 is greater than the outer diameter of the end far from the motor shaft 220.

[0047] In this embodiment, the shape of the double-headed spline shaft 500 is restricted, providing a basis for the installation of the plurality of buffer strips 520 to form an annular structure.

[0048] Refer to Figure 1 , in one embodiment, an annular groove is provided in the middle of the double-headed spline shaft 500 in the length direction, and the strain gauge 600 is arranged at the position of the groove.

[0049] In this embodiment, the middle part of the double-headed spline shaft 500 is designed with a concave shape to form a groove, and its diameter can be basically the same as the diameter of the gear shaft to be tested. When measuring, the strain gauge 600 is attached here, and the strain it receives can be understood as the strain received by the gear shaft, so that the torque value can be accurately measured. In addition, if it is necessary to replace the strain gauge 600, only the front housing 300 needs to be removed to expose the double-headed spline shaft 500 for execution.

[0050] Referring to Figure 1 , in one embodiment, the support sleeve 230 is made of a flexible material, and a tightening sleeve 250 for expanding the outer diameter of the support sleeve 230 is provided on the inner circumference corresponding to the support sleeve 230.

[0051] In this embodiment, the material of the support sleeve 230 can be a polymer, or a composite material formed by laminating (in the radial direction) metal and polymer. The vibration and heat are blocked through the flexible material of the support sleeve 230. The addition of the tightening sleeve 250 realizes the shaping of the support sleeve 230, ensuring that the support sleeve 230 can achieve a buffering effect while realizing the structural strength.

[0052] In one embodiment, both the grating mounting shaft 400 and the motor shaft 220 are cylindrical hollow structures.

[0053] In this embodiment, the material usage of the cylindrical grating mounting shaft 400 and the motor shaft 220 can be reduced, and at the same time, the processing difficulty of the joint structure at the corresponding position with the double-headed spline shaft 500 is also reduced.

[0054] In one embodiment, a rotational speed measurement module and a torque measurement module are provided at the outer end corresponding to the motor shaft 220.

[0055] In this embodiment, the working of the rotational speed measurement module and the torque measurement module can realize the monitoring of the output state of the torque motor 200, including the rotational speed and the output torque. The specific structural types of the rotational speed measurement module and the torque measurement module are not limited, as long as they can achieve the test function.

[0056] In summary, for the gear detection system based on a circular grating provided by the present invention, when the torque motor 200 is normally started or operates at a large torque / high rotational speed, most of the vibrations generated will be absorbed and transmitted by the support sleeve 230. The motor shaft 220 and the grating mounting shaft 400 are connected through the double-headed spline shaft 500. When the vibration is transmitted between the motor shaft 220 and the grating mounting shaft 400, since the double-headed spline shaft 500 has a clearance fit at both ends, part of the vibration and heat transmission will be blocked. This ensures that the operating state and the stable state at the position of the grating mounting shaft 400 are more stable, and finally the test accuracy is also improved.

[0057] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of the present invention.

Claims

1. A gear detection system based on circular grating, characterized in that: include: rear box (100); A torque motor (200) is installed in the rear housing (100), the torque motor (200) comprising a stator part (210), a motor shaft (220), a support sleeve (230) and a rotor part (240), the stator part (210) being circumferentially arranged on the inner wall of the rear housing (100), the motor shaft (220) being rotatably installed on the rear housing (100), the support sleeve (230) being fixed to the outer circumference of the motor shaft (220), and the rotor part (240) being fixed to the outer circumference of the support sleeve (230) to form a match with the stator part (210); A front box body (300) connected to the rear box body (100); A grating installation shaft (400) is rotatably mounted on the front box body (300), and one end of the grating installation shaft (400) away from the motor shaft (220) is connected to a circular grating module; A double-ended spline shaft (500), both ends of which respectively form a spline fit with the grating installation shaft (400) and the motor shaft (220) and a clearance fit in the length direction; A strain gauge (600) is mounted on a peripheral wall of the double-headed spline shaft (500), and the strain gauge (600) detects and sends a strain sensing signal.

2. The gear detection system based on circular grating according to claim 1 is characterized in that: One end of the grating installation shaft (400) away from the motor shaft (220) is connected to a gear measurement module.

3. The gear detection system based on circular grating according to claim 1 is characterized in that: Both ends of the double-headed spline shaft (500) in the length direction respectively clamp an elastic ring (700) with the motor shaft (220) and the grating installation shaft (400) in the length direction.

4. The gear detection system based on circular grating according to claim 1 is characterized in that: The spline fit formed between the double-headed spline shaft (500), the grating installation shaft (400) and the motor shaft (220) is a clearance fit in the circumferential direction.

5. The gear detection system based on circular grating according to claim 4 is characterized in that: A plurality of first spline teeth (510) are arranged on the outer wall of the double-headed spline shaft (500) corresponding to one end of the motor shaft (220), a plurality of second spline teeth corresponding to the plurality of first spline teeth (510) are arranged on the inner wall of the motor shaft (220), and a buffer strip (520) having an L-shaped cross section is arranged between the first spline teeth (510) and the second spline teeth, and the buffer strip (520) is clamped in the thickness direction and the height direction of the first spline teeth (510) and the second spline teeth.

6. The gear detection system based on circular grating according to claim 5 is characterized in that: The front box body (300) is slidably arranged on the rear box body (100) along the length direction.

7. The gear detection system based on circular grating according to any one of claims 1 to 6, characterized in that: An annular groove is provided in the middle of the double-headed spline shaft (500) in the length direction, and the strain gauge (600) is arranged at the position of the groove.

8. The gear detection system based on circular grating according to any one of claims 1 to 6, characterized in that: The support sleeve (230) is made of a flexible material, and a tightening sleeve (250) for expanding the support sleeve (230) is arranged corresponding to the inner circumference of the support sleeve (230).

9. The gear detection system based on circular grating according to any one of claims 1 to 6, characterized in that: The grating installation shaft (400) and the motor shaft (220) are both cylindrical hollow structures.

10. The gear detection system based on circular grating according to any one of claims 1 to 6, characterized in that: A rotation speed measurement module and a torque measurement module are provided at the outer end corresponding to the motor shaft (220).

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