An inner hole size detecting device with progressive adjustment

Abstract

The utility model discloses a kind of inner hole size detection devices of gradual adjustment, including outer tube, measuring rod, propelling spring, movable measuring head, equal-arm door type lever and with cam mechanism centering disc, the propelling spring is sleeved on measuring rod, and one end of propelling spring is contacted with the step of outer tube inner cavity, and the other end is contacted with the end step of measuring rod;The measuring rod is arranged in outer tube, and can be moved along outer tube axial direction;With cam mechanism centering disc is rotatably arranged in the device outer tube by bearing, and is connected with the equal-arm door type lever one end;Movable measuring head is fixedly connected with device outer tube by measuring head fixing rod, and movable measuring head is installed on measuring head fixing rod, and movable measuring head is contacted with the cam mechanism centering disc. The utility model realizes the inner diameter size detection of multiple sections, provides data basis for accurately evaluating the inner diameter size after cylinder adhering magnetic steel and motor stator rotor air gap value.

Description

Technical Field

[0001] This utility model belongs to the field of permanent magnet rotor inner diameter detection technology, and in particular, relates to a progressively adjustable inner hole size detection device. Background Technology

[0002] A certain type of permanent magnet motor produced by a certain company has a rotor with a cylindrical structure, a relatively large inner diameter (D>600mm), and a relatively long axial length (L>1200mm). A magnet with a short axial length is arranged in the middle of the cylinder, and the magnet is attached to the inner wall of the cylinder around its circumference. Due to the attraction of the magnet, commonly used measuring tools for measuring the inner diameter cannot meet the testing requirements.

[0003] For the inner diameter testing of permanent magnet rotors with large inner cylinder diameters, the company's existing testing resources are insufficient. Using qualitative testing or measuring tools with low testing accuracy makes it difficult to quantitatively assess the diameter of different cross sections, and it is impossible to obtain basic data for evaluating the air gap between the stator and rotor and analyzing motor performance.

[0004] Existing patent publication number CN113865468A discloses a special measuring ruler for the air gap between the stator and rotor of a motor, including a housing, a measuring component, and a dial indicator. The housing consists of a base and a gripping component located at the upper end of the base, and the housing has a cavity inside. The measuring component is located inside the cavity of the housing and consists of a core, a rotating component, and a probe. The core and the probe are movably connected through the rotating component, and the core also has a limiting protrusion and a spring. The dial indicator is located at the upper end of the housing, and the lower end of the dial indicator is connected to the upper end of the core. This invention solves the problems of insufficient accuracy and low measurement efficiency in measuring the air gap between the stator and rotor of a motor. However, generator stator and rotor models vary, and the curvature specifications at the air gap are different. Operators need to carry multiple sets of curved probes, and when changing them, the probes at the holes in the base need to be disassembled, which is cumbersome. It is also difficult to quantitatively assess the diameter of different cross-sections. Utility Model Content

[0005] This invention addresses the current limitations of existing technologies for detecting the inner diameter of permanent magnet rotors with large inner cylinder diameters. The company's existing testing resources are insufficient, and qualitative testing or measuring tools with low accuracy are insufficient for quantitatively assessing the diameter of different cross-sections. Consequently, it is impossible to obtain fundamental data for evaluating the air gap between the stator and rotor and analyzing motor performance. Therefore, a progressively adjustable inner hole size detection device is proposed.

[0006] A progressively adjustable internal bore size detection device includes an outer cylinder, a measuring rod, a push spring, a movable probe, an equal-arm portal lever, and a centering disk with a cam mechanism. The push spring is sleeved on the measuring rod, with one end contacting the inner cavity step of the outer cylinder and the other end contacting the end step of the measuring rod. The measuring rod is disposed inside the outer cylinder and can move axially along the outer cylinder. The centering disk with a cam mechanism is rotatably disposed inside the outer cylinder of the device via a bearing and is connected to one end of the equal-arm portal lever. The movable probe is fixedly connected to the outer cylinder of the device via a probe fixing rod, and the movable probe is mounted on the probe fixing rod and contacts the centering disk with a cam mechanism.

[0007] Furthermore, the centering disk of the cam mechanism is a four-lobed cam structure, and the centering disk of the cam mechanism is tapered as a whole; the centering disk of the cam mechanism is connected to the end tapered surface of the equal-arm portal lever, and the end of the centering disk of the cam mechanism is set as a ball head structure.

[0008] Furthermore, the centering disk of the cam mechanism is connected to the outer cylinder by a double-row precision bearing. The inner ring of the double-row precision bearing is interference-fitted with the outer circle of the centering disk of the cam mechanism, and the outer ring of the double-row precision bearing is interference-fitted with the inner wall of the outer cylinder.

[0009] Furthermore, the measuring rod is a stepped rod body, the measuring rod is clearance-fitted with the inner wall of the outer cylinder, and the mounting point of the measuring rod and the inner wall of the outer cylinder is coated with lubricating oil.

[0010] Furthermore, the movable probe has a cylindrical structure with spherical smooth contact heads at both ends, which make smooth contact with the magnet and the cam edge surface through the contact heads.

[0011] Furthermore, a spherical smooth groove is provided at the contact position between the equal-arm portal lever and the centering plate of the cam mechanism, and the equal-arm portal lever is fixedly connected to the outer cylinder by a pin.

[0012] Furthermore, the equal-arm portal lever is provided with an assembly hole, the pin passes through the assembly hole and is fixedly connected to the inner wall of the outer cylinder; the end of the equal-arm portal lever that contacts the centering disk of the cam mechanism is provided with a spherical smooth groove, and the ball head structure of the centering disk of the cam mechanism is embedded in the spherical smooth groove.

[0013] Furthermore, it also includes a rotating handle and a measuring gauge. The rotating handle is threadedly connected to the centering disc with a cam mechanism and is used to drive the centering disc with the cam mechanism to rotate. The measuring gauge is connected to the end of the measuring rod through a locking nut. By axially tightening the locking nut, the end of the measuring rod can be radially contracted, thereby clamping the measuring rod of the measuring gauge.

[0014] Furthermore, the outer cylinder has an internally hollow stepped structure, and the ends of the outer cylinder are configured as a segmented structure.

[0015] Furthermore, the movable probe, probe fixing rod, centering disk with cam mechanism, equal-arm portal lever, internal measuring rod, propulsion spring, outer cylinder, and rotating handle are all made of non-magnetic materials.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model includes an outer cylinder, a measuring rod, a propulsion spring, a movable probe, an equal-arm portal lever, and a centering disk with a cam mechanism. The propulsion spring is sleeved on the measuring rod, with one end of the spring contacting the step inside the outer cylinder and the other end contacting the end step of the measuring rod. The measuring rod is located inside the outer cylinder and can move axially along the outer cylinder. This utility model can adjust the circumferential position of the movable probe by rotating the handle to achieve the dimensional detection of the rotor's inner hole at different positions. At the same time, by adjusting the overall position of the axial movement device in conjunction with the cam mechanism to drive the probe radially, it can achieve quantitative measurement of the diameter of different cross sections (multiple axial positions), ultimately providing complete basic data support for the calculation of the air gap between the stator and rotor and the analysis of motor performance.

[0017] 2. The contact magnet parts (movable probe, probe fixing rod) and the detection rotation parts (centering disk with cam mechanism, equal-arm portal lever, internal measuring rod) of this utility model are all made of non-magnetic materials. This avoids the influence of the magnetic attraction on the component movement (such as probe movement, lever transmission, centering disk rotation) from the structural source, ensuring accurate force transmission and stable detection process, and ultimately achieving accurate quantitative measurement of the inner diameter.

[0018] 3. The structure of this utility model has a certain degree of versatility and can be adapted to different models of cylindrical rotor inner diameters. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the centering disk structure with cam mechanism of this utility model; Figure 3 This is a cross-sectional schematic diagram of the present invention; In the above diagram, 1. Measuring gauge; 2. Locking nut; 3. Measuring rod; 4. Push spring; 5. Equal-arm portal lever; 6. Centering plate with cam mechanism; 7. Outer cylinder; 8. Movable probe; 9. Probe fixing rod; 10. Rotating handle. Detailed Implementation

[0020] To clearly illustrate the technical features of this utility model, the following detailed description, in conjunction with the accompanying drawings, provides a comprehensive understanding of the present utility model. Many specific details are set forth in the following description to facilitate a thorough understanding of the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present utility model is not limited to the specific embodiments disclosed below. Furthermore, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the present utility model and simplifying the description. They 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 the present utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined as "first" and "second" can explicitly or implicitly include one or more of those features. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. In this utility model, unless otherwise explicitly specified and limited, terms such as "installed," "connected," "joined," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. In this utility model, unless otherwise explicitly specified and limited, "on" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0021] Example 1 like Figure 1As shown, a progressively adjustable internal hole size detection device includes an outer cylinder 7, a measuring rod 3, a push spring 4, a movable probe 8, an equal-arm portal lever 5, and a centering disk 6 with a cam mechanism. The push spring 4 is sleeved on the measuring rod 3, and one end of the push spring 4 contacts the step of the inner cavity of the outer cylinder 7, while the other end contacts the end step of the measuring rod 3. The measuring rod 3 is disposed inside the outer cylinder 7 and can move axially along the outer cylinder 7. The centering disk 6 with a cam mechanism is rotatably disposed inside the outer cylinder 7 of the device via a bearing and is connected to one end of the equal-arm portal lever 5. The movable probe 8 is fixedly connected to the outer cylinder 7 of the device via a probe fixing rod 9, and the movable probe 8 is mounted on the probe fixing rod 9 and contacts the centering disk 6 with a cam mechanism.

[0022] For a certain series of cylindrical permanent magnet motor rotors, the inner diameter is 650mm (D>600mm), the axial length is 1300mm (L>1200mm), and neodymium iron boron magnets with an axial length of 150mm are attached to the inner circumference of the inner wall. It is necessary to inspect the inner diameter of multiple key cross-sections of the rotor's inner hole after the magnets are attached, as well as the inner diameter of the circumferential orientation at each cross-section. This is used to accurately measure the diameter and shape error of the inner hole and is suitable for machining, quality inspection, and other scenarios.

[0023] In this embodiment, the outer cylinder 7 is made of stainless steel and has a hollow stepped structure inside. It has an outer diameter of 130mm, an inner diameter of 110mm, and an axial length of 900mm. The end of the outer cylinder 7 has a four-lobed structure with a 0.6mm gap between the lobes for mounting and fixing the measuring gauge 1. The inner wall of the outer cylinder 7 is machined with precision steps to support the push spring 4 and the measuring rod 3. Specifically, the measuring rod 3 passes through the cavity inside the outer cylinder 7, with a clearance fit between the measuring rod 3 and the inner wall of the outer cylinder 7, and the inner wall of the outer cylinder 7 is coated with lubricating oil. One end of the measuring rod 3 has a step for fixing the push spring 4, and the other end is connected to the measuring gauge 1 via a locking nut 2. The measuring gauge 1 is a dial indicator or a micrometer indicator.

[0024] like Figure 1 As shown, the push spring 4 is sleeved on the measuring rod 3. One end of the push spring 4 contacts the step of the inner cavity of the outer cylinder 7, and the other end contacts the end step of the measuring rod 3, providing a constant outward thrust so that the measuring rod 3 is always in the ready position.

[0025] In this embodiment, the movable probe 8 is a cylindrical structure made of polytetrafluoroethylene (non-magnetic) with smooth spherical contact heads at both ends. The probe fixing rod 9 is made of 304 stainless steel and is fully welded to the side wall of the outer cylinder 7. The movable probe 8 is connected to the probe fixing rod 9 via an M14×1.5 thread to ensure the radial position stability of the probe. The movable probe 8 is fixedly connected to the outer cylinder 7 via the probe fixing rod 9. The movable probe 8 contacts the centering disk 6 with a cam mechanism and can move radially when the centering disk rotates.

[0026] like Figure 2 and Figure 3 As shown, the equal-arm portal lever 5 is fixedly connected to the outer cylinder 7 by a pin. One end of the lever has a spherical smooth groove that fits into the ball head structure of the centering disk 6 with a cam mechanism, forming a low-friction rotating pair. The other end of the lever is indirectly linked to the movable probe 8. The centering disk 6 with a cam mechanism has an overall tapered structure with a four-lobed cam profile and a ball head structure. The centering disk is connected to the outer cylinder 7 through double-row precision bearings. The inner ring of the bearing is interference-fitted with the outer circle of the centering disk, and the outer ring of the bearing is interference-fitted with the inner wall of the outer cylinder 7 to ensure smooth rotation.

[0027] In operation, the device is inserted into the inner hole to be measured, and the handle 10 is rotated to drive the centering disk 6 with the cam mechanism to rotate. The cam action pushes the equal-arm portal lever 5 to swing, thereby causing the movable probe 8 to move radially outward until it contacts the inner hole wall. At the same time, the push spring 4 pushes the measuring rod 3 to move axially, and the displacement is displayed through the measuring dial 1, thereby reading the inner hole size. All components are made of non-magnetic materials (such as stainless steel and copper alloy) to avoid magnetic interference. This embodiment has a simple structure, is suitable for conventional inner hole measurement, and can achieve an accuracy of 0.01 mm.

[0028] Example 2 like Figure 1 As shown, a progressively adjustable internal hole size detection device includes an outer cylinder 7, a measuring rod 3, a push spring 4, a movable probe 8, an equal-arm portal lever 5, and a centering disk 6 with a cam mechanism. The push spring 4 is sleeved on the measuring rod 3, with one end of the push spring 4 contacting the step of the inner cavity of the outer cylinder 7 and the other end contacting the end step of the measuring rod 3. The measuring rod 3 is disposed inside the outer cylinder 7 and can move axially along the outer cylinder 7. The centering disk 6 with a cam mechanism is rotatably disposed inside the outer cylinder 7 of the device via a bearing and is connected to one end of the equal-arm portal lever 5. The movable probe 8 is fixedly connected to the outer cylinder 7 of the device via a probe fixing rod 9, and the movable probe 8 is mounted on the probe fixing rod 9 and contacts the centering disk 6 with a cam mechanism.

[0029] Specifically, the cam profile of the centering disk 6 with cam mechanism adopts a logarithmic spiral design, and the four-lobed cam is precision ground to ensure smooth and linear movement of the movable probe 8 during rotation. The ball joint structure of the centering disk head is made of tungsten carbide to improve wear resistance.

[0030] The spherical smooth groove of the equal-arm portal lever 5 is coated with ceramic to reduce friction with the centering disc ball head. The lever is connected to the outer cylinder 7 via a high-precision pin made of tool steel to ensure the lever swings without wobbling. The movable probe 8 is set to its initial position via a fine-tuning mechanism (such as threaded adjustment) on the probe fixing rod 9 to adapt to different apertures. The surface of the measuring rod 3 is polished, and a Teflon coating is used at the clearance where it fits with the outer cylinder 7. The push spring 4 adopts a double-spring parallel design to provide more stable thrust and avoid jamming.

[0031] During operation, the device is pre-calibrated at zero point and then inserted into the inner hole. Rotating handle 10 finely adjusts the centering disc, the movable probe 8 gradually contacts the hole wall, the digital dial indicator displays the diameter value, and the data is analyzed and stored via software. This embodiment offers high measurement accuracy and low repeatability error, making it suitable for high-precision manufacturing and inspection.

[0032] Example 3 like Figure 1 As shown, a progressively adjustable internal hole size detection device includes an outer cylinder 7, a measuring rod 3, a push spring 4, a movable probe 8, an equal-arm portal lever 5, and a centering disk 6 with a cam mechanism. The push spring 4 is sleeved on the measuring rod 3, with one end of the push spring 4 contacting the step of the inner cavity of the outer cylinder 7 and the other end contacting the end step of the measuring rod 3. The measuring rod 3 is disposed inside the outer cylinder 7 and can move axially along the outer cylinder 7. The centering disk 6 with a cam mechanism is rotatably disposed inside the outer cylinder 7 of the device via a bearing and is connected to one end of the equal-arm portal lever 5. The movable probe 8 is fixedly connected to the outer cylinder 7 of the device via a probe fixing rod 9, and the movable probe 8 is mounted on the probe fixing rod 9 and contacts the centering disk 6 with a cam mechanism.

[0033] In this embodiment, the outer cylinder 7 is made of aluminum alloy, reducing its weight by 50%. The internal stepped structure is simplified, and the end segment design is changed to a quick-release snap-on type for easy disassembly and carrying. The measuring gauge 1 is replaced with a 0-5mm range dial indicator (accuracy 0.001mm), and the measuring rod 3 has a diameter of 6mm. The segmented structure of the outer cylinder 7 is adapted to the 6mm measuring rod 3, and the locking nut 2 has an M75×1 fine thread to ensure no radial offset during fixing. The surface of the measuring rod 3 is ground, reducing the gap between it and the inner wall of the outer cylinder 7 to 0.008mm, and it is coated with a special lubricant for precision instruments.

[0034] In this embodiment, the centering disk 6 with cam mechanism adopts a three-lobed cam structure, with a simplified cam profile to reduce machining costs and a reduced overall taper. The centering disk is connected to the outer cylinder 7 via a single-row deep groove ball bearing. The bearings are standard parts and easy to replace. The movable probe 8 has a small cylindrical structure, and the spherical contact head is made of tungsten carbide. The probe fixing rod 9 adopts a quick-release design, allowing for rapid probe replacement to adapt to different bore diameter ranges.

[0035] Obviously, the above-described embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A progressively adjustable internal hole size detection device, characterized in that, The device includes an outer cylinder, a measuring rod, a push spring, a movable probe, an equal-arm portal lever, and a centering disk with a cam mechanism. The push spring is sleeved on the measuring rod, with one end of the push spring contacting the inner cavity step of the outer cylinder and the other end contacting the end step of the measuring rod. The measuring rod is disposed inside the outer cylinder and can move axially along the outer cylinder. The centering disk with a cam mechanism is rotatably disposed inside the outer cylinder of the device via a bearing and is connected to one end of the equal-arm portal lever. The movable probe is fixedly connected to the outer cylinder of the device via a probe fixing rod, and the movable probe is mounted on the probe fixing rod and contacts the centering disk with a cam mechanism.

2. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, The centering disk of the cam mechanism has a four-lobed cam structure, and the centering disk of the cam mechanism is tapered as a whole; the centering disk of the cam mechanism is connected to the end tapered surface of the equal-arm portal lever, and the end of the centering disk of the cam mechanism is set as a ball head structure.

3. The progressively adjustable internal hole size detection device according to claim 2, characterized in that, The centering disk of the cam mechanism is connected to the outer cylinder by a double-row precision bearing. The inner ring of the double-row precision bearing is interference-fitted with the outer circle of the centering disk of the cam mechanism, and the outer ring of the double-row precision bearing is interference-fitted with the inner wall of the outer cylinder.

4. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, The measuring rod is a stepped rod body, and the measuring rod is fitted with the inner wall of the outer cylinder with a clearance fit. The mounting point of the measuring rod and the inner wall of the outer cylinder is coated with lubricating oil.

5. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, The movable probe has a cylindrical structure with spherical smooth contact heads at both ends, which make smooth contact with the magnet and the cam edge surface through the contact heads.

6. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, The equal-arm portal lever is provided with a spherical smooth groove at the contact position between the centering plate of the cam mechanism and the lever, and the equal-arm portal lever is fixedly connected to the outer cylinder by a pin.

7. The progressively adjustable internal hole size detection device according to claim 6, characterized in that, The equal-arm portal lever has an assembly hole, and the pin passes through the assembly hole and is fixedly connected to the inner wall of the outer cylinder; the end of the equal-arm portal lever that contacts the centering disk of the cam mechanism has a spherical smooth groove, and the ball head structure of the centering disk of the cam mechanism is embedded in the spherical smooth groove.

8. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, It also includes a rotating handle and a measuring gauge. The rotating handle is threadedly connected to the centering plate with a cam mechanism and is used to drive the centering plate with the cam mechanism to rotate. The measuring gauge is connected to the end of the measuring rod through a locking nut. By axially tightening the locking nut, the end of the measuring rod can be radially contracted, thereby clamping the measuring rod of the measuring gauge.

9. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, The outer cylinder has an internally hollow stepped structure, and the ends of the outer cylinder are designed as a segmented structure.

10. The progressively adjustable internal hole size detection device according to claim 1, characterized in that, The movable probe, probe fixing rod, centering plate with cam mechanism, equal-arm portal lever, internal measuring rod, propulsion spring, outer cylinder and rotating handle are all made of non-magnetic material.

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