A device for opening the inner hole of a flexible wheel and a clamping method thereof

Abstract

The present invention discloses a device for opening the inner hole of a flexible wheel and a clamping method thereof, and specifically relates to the field of auxiliary technology for processing flexible wheels of harmonic reducers. A device for opening the inner hole of a flexible wheel and a clamping method thereof, wherein a screw assembly comprises a screw and a screw nut arranged on the screw; a tensioning assembly comprises a step mandrel having at least two step shafts of different diameters and a tensioning sleeve assembly sleeved on the outside of the step mandrel; the tensioning sleeve assembly comprises an expansion sleeve composed of a pair of semicircular expansion sleeves separated from each other and an elastic ring; the step mandrel is sleeved on the screw nut, and the semicircular expansion sleeve is sleeved on the step shaft of the step mandrel through an elastic ring; a positioning assembly is arranged at one end of the screw near the step mandrel. The present invention has a simple structure and is easy to operate. It can match flexible wheels with different tolerances and can be replaced and reused. At the same time, in the process of adjusting the size of the expansion sleeve, it does not require too much extrusion force to deform the expansion sleeve, so that the expansion sleeve is in good contact with the inner hole of the flexible wheel.

Description

Technical Field

[0001] The invention relates to the technical field of flexible wheel processing auxiliary of a harmonic reducer, and in particular to a flexible wheel inner hole expansion device and a clamping method thereof. Background Art

[0002] In the process of mechanical parts processing and inspection, it is necessary to set a benchmark to make the inspection results of the mechanical parts more accurate. At the same time, when the mechanical parts are thin, they are prone to deformation. In order to ensure the accuracy of their inspection, auxiliary inspection devices need to be added to ensure that the mechanical parts are in their normal state.

[0003] Harmonic reducer is a kind of mechanical transmission device that mainly relies on flexible parts to generate elastic mechanical waves to transmit power and motion. Harmonic drive includes three basic components: wave generator, flexible wheel and rigid wheel. One of the three components is fixed at will, and one of the other two is active and the other is driven, which can achieve deceleration or acceleration (fixed transmission ratio), or it can be transformed into two inputs and one output to form a differential transmission. Harmonic drive has the advantages of large transmission ratio and wide range, high precision, small backlash, large load-bearing capacity, small size, light weight, high transmission efficiency, stable transmission, low noise, and the ability to transmit motion to confined spaces. It has been more and more widely used in recent years.

[0004] The flexible wheel of the harmonic reducer is the core part of the harmonic reducer. The processing accuracy directly affects the transmission accuracy and service life of the reducer. Due to its special structure, it is thin-walled after processing and elliptical in the free state. Therefore, when processing and testing it, it must be positioned with a mandrel to make the inner hole round. However, there is a tolerance in the size of the inner hole, so the mandrel must be adjustable in size. The mandrels used nowadays mostly rely on hydraulic or magnetic power, and are matched with machine tools to make a set of complex tooling. They can be processed on machine tools, but when other equipment such as gear measuring instruments are needed for testing after processing, this type of mandrel loses its support force and becomes an unadjustable mandrel, which cannot meet the detection requirements of the inner holes of flexible wheels of multiple sizes, resulting in inaccurate detection results, which increases the difficulty of new product development. Summary of the invention

[0005] The purpose of the present invention is to provide a device for expanding the inner hole of a flexible wheel and a clamping method thereof, so as to solve the problem that the existing step mandrel cannot be used multiple times and can be adjusted to multiple sizes, and requires too much extrusion force to cause the expansion sleeve in contact with the flexible wheel to deform.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] A device for expanding the inner hole of a flexible wheel comprises: a screw assembly, a tensioning assembly and a positioning assembly; the screw assembly comprises a screw and a screw nut arranged on the screw; the tensioning assembly comprises a step mandrel with at least two steps of different diameters and a tensioning sleeve assembly sleeved on the step mandrel; the step mandrel is sleeved on the screw nut and connected to the screw nut; the tensioning sleeve assembly comprises an annular expansion sleeve composed of a pair of semicircular expansion sleeves separated from each other and an elastic ring arranged on the outer circumference of the expansion sleeve for connecting the two semicircular expansion sleeves; the expansion sleeve is sleeved on one of the steps of the step mandrel; and positioning assemblies are respectively provided at both ends of the screw.

[0008] The beneficial effects of the above technical solution are as follows: by connecting the step mandrel with the screw nut, and the screw nut is arranged on the screw, the step mandrel can slide up and down along the screw as the screw nut slides on the screw, and the position of the step mandrel on the screw is adjusted, so that the diameter of the step mandrel matches the flexible wheel with different inner hole diameters, and the adjustment of flexible wheels of different sizes is achieved. By setting a pair of semicircular expansion sleeves separated from each other on the outside of the step mandrel, the semicircular expansion sleeves are in contact with the flexible wheel, avoiding direct contact between the flexible wheel and the step mandrel, causing certain damage to the step mandrel, and thus affecting the accuracy of the step mandrel; on the other hand, the elastic ring connects a pair of semicircular expansion sleeves separated from each other together and sets them on the step mandrel, and can adjust and change the size of the expansion sleeve composed of a pair of semicircular expansion sleeves separated from each other according to the step shaft with different diameters of the step mandrel to adapt to the size of the inner hole of the flexible wheel. A pair of semicircular expansion sleeves separated from each other are connected together by an elastic ring to form an expansion sleeve, so that in the process of adjusting the size of the expansion sleeve, there will be no excessive deformation of the expansion sleeve. At the same time, no too large squeezing force is required in the process of adjustment, and the purpose of adjusting the size of the expansion sleeve can be achieved, and it can be used multiple times.

[0009] Furthermore, the expansion sleeve is arranged on the step with the smallest diameter of the step core shaft.

[0010] The beneficial effect of adopting the above technical solution is: by arranging the expansion sleeve on a step with the smallest diameter of the step mandrel, the expansion sleeve can be sleeved on other steps on the step mandrel, thereby satisfying the tensioning and supporting function of the expansion sleeve.

[0011] Furthermore, a flange is provided at one end of the lead screw nut, and the flange is connected to the small end face of the step core shaft through bolts.

[0012] The beneficial effects of adopting the above technical solution are as follows: by setting a flange at one end of the screw nut, the step mandrel sleeved on the screw nut is fixedly connected to the screw nut. When adjusting the position of the step mandrel, rotate the step mandrel so that the screw nut drives the step mandrel to slide on the screw. The flange is connected to the small end face of the step mandrel, which makes the structure of the opening device of the inner hole of the flexible wheel compact and beautiful without affecting the processing and detection of the inner hole of the flexible wheel; on the other hand, when changing the position of the step mandrel on the screw, the positioning assembly installed on the screw can tighten the step mandrel again. At the same time, the flange on the screw nut is connected to the small end face of the step mandrel, so that in the process of detecting the inner hole of the flexible wheel, it is convenient to insert the flexible wheel into the outer circumference of the step mandrel, avoiding the inability to sleeve the flexible wheel on the outside of the step mandrel due to the obstruction of the fixed assembly.

[0013] Furthermore, a groove is arranged on the outer circumferential surface of the semicircular expansion sleeve, so that the outer circumferential surface of the expansion sleeve has an annular groove, and the elastic ring is arranged inside the annular groove.

[0014] The beneficial effect of adopting the above technical solution is: by arranging a groove on the outer circumferential surface of the semicircular expansion sleeve and placing the elastic ring inside the groove, the surface where the expansion sleeve formed by a pair of semicircular expansion sleeves separated from each other contacts with the flexible wheel is smooth and free of protrusions, thereby avoiding damage to the inner hole surface of the flexible wheel and affecting the accuracy of the flexible wheel.

[0015] Furthermore, the semicircular expansion sleeve is made of polytetrafluoroethylene; and the elastic ring is a spring connected end to end.

[0016] The beneficial effects of the above technical solution are as follows: by making the semicircular expansion sleeve of polytetrafluoroethylene material, the contact between the expansion sleeve formed by a pair of separated semicircular expansion sleeves and the inner hole of the flexible wheel has a very small friction force, avoiding the friction between the expansion sleeve and the inner hole of the flexible wheel, and damaging the surface of the inner hole of the flexible wheel. The elastic ring is set as a spring connected end to end, so that the expansion sleeve formed by a pair of separated semicircular expansion sleeves has a certain reset and compression function and a high fatigue resistance, avoiding the phenomenon of insufficient elasticity during long-term use.

[0017] Furthermore, both ends of the screw rod are respectively provided with tips.

[0018] The beneficial effects of adopting the above technical solution are: by setting the tips at both ends of the screw rod, the expansion device can be set on a lathe to carry out small-batch flexible wheel gear processing; at the same time, the expansion device is fixed, which is convenient for detecting the flexible wheel fixed on the expansion device.

[0019] Furthermore, the diameters of two adjacent steps on the step mandrel differ by 0.01 mm.

[0020] The beneficial effect of adopting the above technical solution is: by setting the diameters of two adjacent steps to differ by 0.01 mm, the step mandrel can match the inner holes of the flexible wheel with different tolerances, while also ensuring that the flexible wheel has sufficient accuracy.

[0021] Furthermore, the positioning assembly is arranged on the end face of the large end of the step mandrel, and the positioning assembly includes a nut and a gasket.

[0022] The beneficial effect of adopting the above technical solution is: by setting the positioning component on the end face of the screw rod close to the large end of the step core shaft, the step core shaft and the screw rod are fixed by a nut; at the same time, when adjusting the position of the step core shaft, the step core shaft can be tightened again.

[0023] A flexible pulley clamping method based on the above-mentioned flexible pulley inner hole expansion device comprises the following steps:

[0024] S1. Install the expansion sleeve on the step with the largest diameter of the step mandrel. At this time, there is a gap between the two semicircular expansion sleeves, and install one of the positioning components on the end of the screw rod close to the large end of the step mandrel, so that the screw nut is fixed on the screw rod;

[0025] S2. Slip the flexible wheel onto the screw rod from one end of the screw rod close to the small end of the step mandrel, and extend the small end of the step mandrel from the open end of the flexible wheel into the interior of the flexible wheel; install another positioning assembly on the screw rod and make it contact with the open end of the flexible wheel;

[0026] S3. Place the large end of the step mandrel upwards;

[0027] S4, loosen the positioning assembly near the large end of the step mandrel;

[0028] S5. Twist the step mandrel to bring the expansion sleeve close to the open end of the flexible wheel, and determine whether the open end of the flexible wheel can be mounted on the expansion sleeve; if it can be mounted on the expansion sleeve, tighten the positioning assembly close to the large end of the step mandrel; if it cannot be mounted on the expansion sleeve, proceed to the next step;

[0029] S6, screw the step mandrel to move the step mandrel downward, push the expansion sleeve to the next step, and repeat step S5 until the open end of the flexible wheel can be sleeved on the expansion sleeve.

[0030] The beneficial effects of the above technical solution are as follows: by cooperating with the lead screw and the lead screw nut, and fixing the step mandrel on the lead screw nut, when the step mandrel is rotated, the lead screw nut drives the step mandrel to slide on the lead screw, so that the adjustment process is smooth and convenient; by adjusting the size of the expansion sleeve composed of a pair of semicircular expansion sleeves, the step mandrel with a step shaft of different diameters can be matched. The adjustment process of the inner hole of the flexible wheel adopts a semi-automatic method, which can be accurately adjusted according to the actual tolerance of the inner hole of the flexible wheel, so that the expansion sleeve composed of a pair of semicircular expansion sleeves and the inner hole of the flexible wheel are well matched. After the inner hole of the flexible wheel is adjusted, the adjustment device is clamped on the machine tool, and the flexible wheel is subjected to gear processing or precision inspection. By setting a positioning component at one end close to the outside of the flexible wheel, the flexible wheel body can be fixed on the lead screw and the expansion sleeve, avoiding the phenomenon of the flexible wheel body slipping off the expansion sleeve during the processing and inspection of the flexible wheel body.

[0031] Furthermore, when judging whether the open end of the flexible pulley can be sleeved on the expansion sleeve, the shape of the open end of the flexible pulley is manually adjusted.

[0032] The beneficial effect of adopting the above technical solution is that the shape of the open end of the flexible wheel can be manually adjusted so that the flexible wheel can be smoothly sleeved on the expansion sleeve.

[0033] The present invention has the following beneficial effects:

[0034] 1. The adjusting device of the present invention has a simple structure and is easy to operate. It can match flexible wheels with different tolerances and can be replaced and reused. At the same time, in the process of adjusting the size of the expansion sleeve, there is no need for too much extrusion force to deform the expansion sleeve, so that the expansion sleeve and the inner hole of the flexible wheel are in good contact.

[0035] 2. The step mandrel with step shafts of different diameters of the present invention enables the step mandrel to match the flexible wheel sizes with different tolerances, and after the flexible wheel inner hole is adjusted, a certain supporting force is provided during the processing of the flexible wheel.

[0036] 3. A pair of semicircular expansion sleeves separated from each other in the present invention are connected together by an elastic ring and are sleeved on the step core shaft. They can be adjusted to different sizes according to different step shaft sizes on the step core shaft to match the inner holes of the flexible wheel with different tolerances; the expansion sleeves are arranged as a pair of semicircular expansion sleeves separated from each other, so that the adjustment process is lighter and simpler, and the size of the expansion sleeve can be adjusted without too much extrusion force.

[0037] 4. The present invention provides positioning components at one end of the screw rod close to the flexible wheel body and at the other end close to the large end of the step core shaft, so that the flexible wheel body can be stably installed on the outside of the step core shaft, avoiding the flexible wheel from slipping out of the step core shaft during processing or testing of the flexible wheel. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a structural schematic diagram of the opening device of the inner hole of the flexible wheel of the present invention;

[0039] Figure 2 It is a schematic diagram of the step mandrel structure of the present invention;

[0040] Figure 3 It is a schematic diagram of the expansion sleeve structure of the present invention;

[0041] Figure 4 It is a schematic diagram of the structure of the screw rod assembly of the present invention;

[0042] Figure 5 It is a schematic structural diagram of the flexible wheel clamping method of the present invention.

[0043] In the figure: 1-screw assembly; 2-tensioning assembly; 3-positioning assembly; 4-flexible wheel; 11-screw; 12-screw nut; 13-positioning countersunk hole; 21-stepped mandrel; 22-tensioning sleeve assembly; 23-expansion sleeve; 24-elastic ring; 25-semicircular expansion sleeve; 121-flange; 251-groove. DETAILED DESCRIPTION

[0044] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0045] Example

[0046] Please refer to Figure 1 A device for expanding the inner hole of a flexible wheel comprises a screw assembly 1, a tensioning assembly 2 and a positioning assembly 3; the tensioning assembly 2 is sleeved on the outside of the screw assembly 1, and the tensioning assembly 2 is fixed to the screw assembly 1 through the positioning assembly 3, so that the tensioning assembly 2 can slide up and down with the screw assembly 1 to match the inner hole of the flexible wheel with different tolerances, and is fixedly sleeved on the tensioning assembly 2, so as to facilitate further processing or detection operations on the flexible wheel.

[0047] Please refer to Figures 1 to 3, a step mandrel 21 having 5 step shafts of different diameters, the 5 step shafts of different diameters are arranged in sequence from the small end to the large end, and the diameters of two adjacent step shafts differ by 0.01mm. By making the diameters of the step shafts of the step mandrel 21 differ by 0.01mm, the step mandrel 21 can match the inner hole of the flexible wheel with different tolerances, so as to achieve the adjustment of the inner hole of the flexible wheel with different size tolerances. The expansion sleeve 23 is composed of a pair of semicircular expansion sleeves 25 separated from each other, and the semicircular expansion sleeves 25 separated from each other are sleeved on the step shafts of different sizes on the step mandrel 21 through the elastic ring 24, so that the semicircular expansion sleeve 25 is in contact with the inner hole of the flexible wheel, avoiding direct contact between the inner hole of the flexible wheel and the step mandrel 21, causing certain damage and destruction to the step mandrel 21, and thus affecting the accuracy of the step mandrel 21. By adjusting the size of the expansion sleeve 23 to match different tolerances of the inner hole of the flexible wheel, and setting the expansion sleeve 23 on different step shafts of the step mandrel 21, the expansion sleeve 23 can still support the flexible wheel after the size is changed, which is convenient for subsequent further processing or testing operations. The expansion sleeve 23 is set as a pair of semicircular expansion sleeves 25 separated from each other, so that the process of adjusting the size of the expansion sleeve 23 is simpler and faster, avoiding excessive deformation during the process of tightening the expansion sleeve 23, so that the expansion sleeve 23 cannot be restored to its original state; and a large extrusion force is required to deform the expansion sleeve 23, and it is difficult to control the actual size of the extrusion force during the adjustment process, which is easy to damage the flexible wheel.

[0048] A groove 251 is provided on the outer circumferential surface of the semicircular expansion sleeve 25, and the notch width of the groove 251 is less than or equal to the width of the semicircular expansion sleeve 25. By providing the groove 251 on the outer circumferential surface of the semicircular expansion sleeve 25, the elastic ring 24 is placed inside the groove 251, so that the outer circumferential surface of the semicircular expansion sleeve 25 is as smooth as possible without protrusions, avoiding damage to the inner hole surface of the flexible wheel and affecting the precision of the flexible wheel.

[0049] The material of the semicircular expansion sleeve 25 is set to be polytetrafluoroethylene material, so that the expansion sleeve 23 formed by a pair of separated semicircular expansion sleeves 25 and the contact point of the flexible wheel inner hole have very small friction, avoiding the friction between the expansion sleeve 23 and the flexible wheel inner hole, causing damage to the surface of the flexible wheel inner hole, and further affecting the accuracy of the flexible wheel inner hole. The elastic ring 24 is set as a spring connected end to end, so that the expansion sleeve 23 formed by a pair of separated semicircular expansion sleeves 25 has a certain reset and compression function and high fatigue resistance, avoiding the phenomenon of insufficient elasticity of the expansion sleeve 23 during long-term use.

[0050] Please refer to Figure 1 and Figure 4The screw assembly 1 includes a screw 11 and a screw nut 12 mounted on the screw 11. The tensioning assembly 2 is sleeved on the outer circumferential surface of the screw nut 12, and the tensioning assembly 2 and the screw nut 12 are fixedly connected by bolts. When adjusting the tensioning assembly 2, the tensioning assembly 2 is driven by the screw nut 12 to slide up and down along the screw 11, thereby achieving the purpose of adjusting the inner hole size of the step flexible wheel.

[0051] A flange 121 is provided at one end of the lead screw nut 12, and the flange 121 is fixed to the small end of the step mandrel 21 by bolts. By providing the flange 121 at one end of the lead screw nut 12, the connection between the step mandrel 21 and the lead screw nut 12 is more firm and stable; at the same time, during the rotation of the step mandrel 21, the lead screw nut 12 can stably and accurately drive the step mandrel 21 to slide up and down along the screw 11.

[0052] A positioning assembly 3 is provided at one end of the screw rod 11 close to the large end of the step mandrel 21. The positioning assembly 3 includes a nut and a gasket. By providing a positioning assembly 3 at the large end of the step mandrel 21, the step mandrel 21 is fixed on the screw rod 11 to prevent the step mandrel 21 from sliding up and down along the screw rod 11 under the action of the lead screw nut 12.

[0053] Positioning countersunk holes 13 are respectively provided at both ends of the screw rod 11, and the positioning countersunk holes 13 are arranged along the axial direction of the screw rod 11. By arranging the positioning countersunk holes 13 at both ends of the screw rod 11 along the axis of the screw rod 11, when the screw rod 11 is installed on a machine tool, good coaxiality is ensured, which facilitates the inspection and processing of the flexible wheel.

[0054] The flexible wheel 4 includes an open end and a hole end. The open end is sleeved on the expansion sleeve 23, and the hole end is sleeved on the screw rod 11. The positioning assembly 3 is installed on the hole end.

[0055] Please refer to Figures 1 to 5 A method for clamping a flexible wheel based on the above-mentioned flexible wheel inner hole expansion device comprises the following steps:

[0056] S1, the expansion sleeve 23 is sleeved on the step with the largest diameter of the step mandrel 21, at this time there is a gap between the two semicircular expansion sleeves 25, and one of the positioning components 3 is installed on the end of the screw rod 11 close to the large end of the step mandrel 21, so that the screw nut 12 is fixed on the screw rod 11;

[0057] S2, sleeve the flexible wheel from one end of the screw rod 11 close to the small end of the step mandrel 21 onto the screw rod 11, and make the small end of the step mandrel 21 extend from the open end of the flexible wheel 4 into the interior of the flexible wheel 4; install another positioning assembly 3 on the screw rod 11 and make it contact with the open end of the flexible wheel;

[0058] S3, the large end of the step mandrel 21 is facing upward;

[0059] S4, loosen the positioning assembly 3 near the large end of the step mandrel 21;

[0060] S5, screw the step mandrel 21 to make the expansion sleeve 23 close to the open end of the flexible wheel 4, adjust the shape of the open end of the flexible wheel 4 by hand, and judge whether the open end of the flexible wheel 4 can be sleeved on the expansion sleeve 23; if it can be sleeved on the expansion sleeve 23, tighten the positioning component 3 close to the large end of the step mandrel 21; if it cannot be sleeved on the expansion sleeve 23, proceed to the next step;

[0061] S6, screw the step mandrel 21 to move the step mandrel 21 downward, and push the expansion sleeve 23 to the next step, and repeat step S5 until the open end of the flexible wheel 4 can be sleeved on the expansion sleeve 23.

[0062] When expanding the size of the inner hole of the flexible wheel, a semi-automatic adjustment method is adopted, which can adjust the step mandrel and the expansion sleeve on the step mandrel according to the tolerance of the actual flexible wheel inner hole, thereby expanding its application range and meeting the needs of processing or testing operations of flexible wheel inner holes of multiple sizes.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for clamping a flexible wheel of a device for opening the inner hole of a flexible wheel, characterized in that: The expansion device for the inner hole of the flexible wheel comprises: a screw rod assembly (1), a tensioning assembly (2) and a positioning assembly (3); The screw assembly (1) comprises a screw (11) and a screw nut (12) arranged on the screw (11); The tensioning assembly (2) comprises a step mandrel (21) having at least two steps of different diameters and a tensioning sleeve assembly (22) sleeved on the step mandrel (21); The step mandrel (21) is sleeved on the lead screw nut (12) and connected to the lead screw nut (12); The tension sleeve assembly (22) comprises an annular expansion sleeve (23) composed of a pair of semicircular expansion sleeves (25) separated from each other, and an elastic ring (24) arranged on the outer circumferential surface of the expansion sleeve (23) for connecting the two semicircular expansion sleeves (25); the expansion sleeve (23) is sleeved on one of the steps of the step core shaft (21); the positioning assemblies (3) are respectively arranged at both ends of the screw rod (11); The flexible wheel clamping method is as follows: S1, sleeve the expansion sleeve (23) onto the step with the largest diameter of the step mandrel (21), so that there is a gap between the two semicircular expansion sleeves (25), and install one of the positioning components (3) on the end of the screw rod (11) close to the large end of the step mandrel (21), so that the screw nut is fixed on the screw rod (11); S2, sleeve the flexible wheel (4) onto the screw rod (11) from one end of the screw rod (11) close to the small end of the step core shaft (21), and allow the small end of the step core shaft (21) to extend from the open end of the flexible wheel (4) into the interior of the flexible wheel (4); install another positioning component (3) on the screw rod (11) and contact it with the open end of the flexible wheel (4); S3, turn the large end of the step mandrel (21) upward; S4, loosen the positioning assembly (3) near the large end of the step mandrel (21); S5: The step mandrel (21) is screwed to bring the expansion sleeve (23) close to the open end of the flexible wheel (4), and it is determined whether the open end of the flexible wheel (4) can be mounted on the expansion sleeve (23); if it can be mounted on the expansion sleeve (23), the positioning assembly (3) close to the large end of the step mandrel (21) is tightened; if it cannot be mounted on the expansion sleeve (23), the next step is performed; S6: The step mandrel (21) is screwed to move the step mandrel (21) downward, and the expansion sleeve (23) is moved to the next step, and step S5 is repeated until the open end of the flexible wheel (4) can be sleeved on the expansion sleeve (23).

2. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to claim 1, characterized in that: When judging whether the open end of the flexible wheel (4) can be sleeved on the expansion sleeve (23), the shape of the open end of the flexible wheel (4) is manually adjusted.

3. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to claim 1, characterized in that: A flange (121) is provided at one end of the lead screw nut (12), and the flange (121) is connected to the small end surface of the step core shaft (21) via bolts.

4. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to claim 1, characterized in that: A groove (251) is provided on the outer circumferential surface of the semicircular expansion sleeve (25), so that the outer circumferential surface of the expansion sleeve (23) has an annular groove, and the elastic ring (24) is arranged inside the annular groove.

5. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to claim 4, characterized in that: The semicircular expansion sleeve (25) is made of polytetrafluoroethylene material; the elastic ring (24) is a spring connected end to end.

6. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to claim 1, characterized in that: Positioning countersunk holes (13) are respectively provided at both ends of the screw rod (11).

7. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to claim 1, characterized in that: The diameters of two adjacent steps on the step mandrel (21) differ by 0.01 mm.

8. The method for clamping a flexible wheel of a flexible wheel inner hole expansion device according to any one of claims 1 to 5, characterized in that: The positioning assembly (3) comprises a nut and a gasket.

Images