Internal grinding clamp for magnetic steel thin-wall wrapped pipe of permanent magnet motor

Abstract

The utility model discloses a fixture for grinding the inner circle of a magnetic steel thin-wall wrapped pipe of a permanent magnet motor. The fixture comprises an inner centering die and an outer centering die, an outer circle positioning surface is arranged on the circumferential outer surface of the inner centering mold, a first axial through hole is formed in the inner centering mold, a first inner conical surface is formed on the inner wall of the first axial through hole, and the first inner conical surface is provided with a first conical surface small end and a first conical surface large end; the outer centering die is provided with a second axial through hole, the inner wall of the second axial through hole is sequentially provided with an inner matching surface and a second inner conical surface in the axial direction, the inner matching surface is suitable for being in sliding fit with the outer circle positioning surface of the inner centering die, the second inner conical surface is adjacent to the inner matching surface, and the second inner conical surface is provided with a second conical surface small end and a second conical surface large end; wherein the outer circle positioning surface of the inner centering die is in sliding fit with the inner matching surface of the outer centering die. The thin-wall workpiece inner circle grinding device can avoid the problems of insufficient precision, poor stability and the like in the thin-wall workpiece inner circle grinding process, and can adapt to thin-wall workpieces with different diameters.

Description

TECHNICAL FIELD

[0001] The utility model relates to a permanent magnet motor magnetic steel thin wall wrapping pipe inner circle grinding fixture belongs to motor production technical field. BACKGROUND

[0002] At present, in the high speed motor spindle manufacturing, the rotor asynchronous type design is usually adopted. When the rotating speed reaches a certain value, the induction current in the rotor squirrel cage of the asynchronous type rotor after loading can produce a large amount of heat due to the slip. Unlike the stator heat, this rotor internal heat is difficult to remove to the motor spindle body, and can cause the rotor to burn out in serious cases.

[0003] The permanent magnet rotor motor can partially solve the heating problem, and with the progress of high speed motor manufacturing technology, this structure has become the development direction. However, due to the high requirement of the rotor magnetic steel wrapping, the insufficient wrapping strength can cause the magnetic steel and the rotor to separate at high speed. Although the carbon fiber wrapping solves the strength problem, the concentricity cannot reach high precision, which affects the development of high speed performance. Therefore, the outer layer of the rotor needs to be wrapped with a high strength alloy sleeve. In order to keep the pre-stress of the alloy sleeve in the best state, the inner circle of the alloy sleeve must be ground. However, the alloy sleeve is a thin-walled pipe structure, which is difficult to fix during inner circle grinding, resulting in difficult control of grinding size, so that high precision pre-stress control becomes very difficult.

[0004] After searching the prior art, it is found that the Chinese patent with publication number CN107225503A discloses a clamp for grinding the inner hole of a thin-walled long sleeve. In this patent, the thin-walled long sleeve workpiece is clamped by the conical chuck. However, it is found that the split structure of the conical chuck may produce uneven pressure distribution during clamping, affecting the concentricity and roundness of the workpiece. SUMMARY

[0005] The technical problem to be solved by the utility model is to overcome the defects of the prior art, and provide a permanent magnet motor magnetic steel thin wall wrapping pipe inner circle grinding clamp, which can avoid the problems of insufficient precision and poor stability in thin wall workpiece inner circle grinding, and can adapt to thin wall workpieces of different diameters.

[0006] In order to solve the above technical problems, the technical scheme of the utility model is as follows: a permanent magnet motor magnetic steel thin wall wrapping pipe inner circle grinding clamp, comprising:

[0007] The inner centering die is provided with an outer circle positioning surface on the circumferential outer surface, the inner centering die is provided with a first axial through hole, the inner wall of the first axial through hole forms a first inner taper surface, and the first inner taper surface is provided with a first taper surface small end and a first taper surface large end;

[0008] An outer centering die is provided with a second axial through hole, an inner matching surface adapted to slide fit with an outer circle positioning surface of the inner centering die and a second inner taper surface adjacent to the inner matching surface are sequentially arranged on an inner wall of the second axial through hole in an axial direction, and the second inner taper surface is provided with a second taper small end and a second taper large end;

[0009] When the outer circle positioning surface of the inner centering die is in sliding fit with the inner matching surface of the outer centering die, the first taper large end of the first inner taper surface and the second taper large end of the second inner taper surface are oppositely arranged to form a taper space adapted to clamp a thin-walled circular ring workpiece.

[0010] Further, in order to facilitate the connection of the inner centering die and the outer centering die, the inner centering die is provided with a circular truncated cone structure extending radially outward, and at least one screw through slot is arranged on the circular truncated cone structure;

[0011] One end of the outer centering die is provided with a fitting surface adapted to fit with the circular truncated cone structure of the inner centering die, and a threaded hole corresponding to the position of the screw through slot is arranged on the fitting surface of the outer centering die.

[0012] Further, the screw through slot on the circular truncated cone structure of the inner centering die is provided with four, and the fitting surface of the outer centering die is provided with four threaded holes corresponding to the positions of the screw through slots.

[0013] Further, the taper angle of the first inner taper surface of the inner centering die is 2° to 12°.

[0014] Further, the taper angle of the second inner taper surface of the outer centering die is the same as that of the first inner taper surface of the inner centering die.

[0015] Further, the inner centering die and the outer centering die are both made of hard alloy material.

[0016] Further, the first axial through hole of the inner centering die is further provided with an inner circle segment coaxially arranged, the inner circle segment is arranged at a position adjacent to the first taper large end of the first inner taper surface, and the inner diameter of the inner circle segment is greater than the diameter of the first inner taper surface at the first taper large end.

[0017] By adopting the above technical scheme, the utility model has the following beneficial effects:

[0018] In the utility model, first, the thin-walled circular ring workpiece is placed between the first inner taper surface of the inner centering die and the second inner taper surface of the outer centering die, and the outer circle positioning surface of the inner centering die is slidably connected with the inner matching surface of the outer centering die to realize relative positioning.

[0019] In addition, the inner centering die is provided with a circular table structure extending radially outward, and is connected with the threaded hole of the outer centering die through the screw through slot, so that the two can be fixed through the screw, stable clamping is realized, and the relative sliding position can also be adjusted according to the requirement, so that the positioning precision is further improved, and the fixture is adapted to workpieces of different specifications.

[0020] In conclusion, the utility model realizes high-precision positioning of the thin-walled circular ring workpiece, effectively prevents axial displacement or deformation of the workpiece, guarantees the stability of the grinding process, and improves the machining precision and consistency. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a three-dimensional structure schematic view of the permanent magnet motor magnetic steel thin-walled wrapping pipe inner circle grinding fixture of the utility model;

[0022] Figure 2 It is a front view of the permanent magnet motor magnetic steel thin-walled wrapping pipe inner circle grinding fixture of the utility model;

[0023] Figure 3 It is Figure 2 the sectional view of A-A;

[0024] Figure 4 It is a structure schematic view of the permanent magnet motor magnetic steel thin-walled wrapping pipe inner circle grinding fixture of the utility model. DETAILED DESCRIPTION

[0025] In order to make the content of the utility model more easily understood clearly, the utility model is further explained in detail below according to specific embodiment and in conjunction with the drawings.

[0026] As Figures 1 to 4 shown, a permanent magnet motor magnetic steel thin-walled wrapping pipe inner circle grinding fixture comprises:

[0027] The circumferential outer surface of the inner centering die 1 is provided with an outer circle positioning surface, the inner centering die 1 is provided with a first axial through hole, the inner wall of the first axial through hole is formed with a first inner taper surface, and the first inner taper surface is provided with a first taper small end and a first taper large end;

[0028] The outer centering die 2 is provided with a second axial through hole, and the inner wall of the second axial through hole is sequentially provided with an inner matching surface adapted to be slidingly matched with the outer circle positioning surface of the inner centering die 1 and a second inner taper surface adjacent to the inner matching surface in the axial direction, and the second inner taper surface is provided with a second taper small end and a second taper large end.

[0029] When the outer circle positioning surface of the inner centering die 1 is slidingly matched with the inner matching surface of the outer centering die 2, the first taper large end of the first inner taper surface is oppositely arranged with the second taper large end of the second inner taper surface, forming a taper space adapted to clamp the thin-walled annular workpiece 3.

[0030] In this embodiment, as shown in Figures 1 to 4 , first, the thin-walled annular workpiece 3 is placed between the first inner taper surface of the inner centering die 1 and the second inner taper surface of the outer centering die 2, and the outer circle positioning surface of the inner centering die 1 is slidingly matched with the inner matching surface of the outer centering die 2 to realize relative positioning. At this time, the first inner taper surface of the inner centering die 1 and the second inner taper surface of the outer centering die 2 jointly form a taper space, and the relative arrangement of the first taper large end and the second taper large end reliably limits the thin-walled annular workpiece 3 in the axial direction.

[0031] Specifically, as shown in Figures 1 to 4 , the inner centering die 1 is provided with a circular truncated cone structure extending radially outward, and the circular truncated cone structure is provided with four screw through grooves;

[0032] One end of the outer centering die 2 is provided with a fitting surface adapted to cooperate with the circular truncated cone structure of the inner centering die 1, and the fitting surface of the outer centering die 2 is provided with screw holes corresponding to the positions of the screw through grooves.

[0033] Specifically, as shown in Figures 1 to 4 , the four screw through grooves on the circular truncated cone structure of the inner centering die 1 are provided, and the fitting surface of the outer centering die 2 is provided with four screw holes corresponding to the positions of the screw through grooves.

[0034] In this embodiment, as shown in Figures 1 to 4 , the embodiment further includes a fastener, and the fastener is adapted to pass through the screw through groove and be screwed into the screw hole to detachably connect the inner centering die 1 and the outer centering die 2. The screw through groove allows fine adjustment during connection to ensure that the taper space formed by the first inner taper surface and the second inner taper surface can accurately accommodate the thin-walled annular workpiece 3.

[0035] When it is necessary to install or dismount the thin-walled annular workpiece 3, the fastener can be loosened to separate the inner centering die 1 and the outer centering die 2. After the workpiece replacement is completed, the inner centering die 1 and the outer centering die 2 are reassembled and fastened. The four evenly distributed connection points ensure the overall stability of the clamp during the grinding process, and the fastener is an adjusting screw.

[0036] Specifically, as shown in Figures 1 to 4As shown, the taper angle of the first inner taper surface of the inner centering die 1 is 2° to 12°.

[0037] Specifically, as shown in Figures 1 to 4 As shown, the taper angle of the second inner taper surface of the outer centering die 2 is the same as that of the first inner taper surface of the inner centering die 1.

[0038] Specifically, as shown in Figures 1 to 4 As shown, the inner centering die 1 and the outer centering die 2 are both made of hard alloy material.

[0039] Specifically, as shown in Figures 1 to 4 As shown, the first axial through hole of the inner centering die 1 is further provided with an inner circular segment coaxially arranged at the adjacent position of the first taper large end of the first inner taper surface, and the inner diameter of the inner circular segment is greater than the diameter of the first inner taper surface at the first taper large end.

[0040] In this embodiment, as shown in ​ As shown, the taper angle of the first inner taper surface of the inner centering die 1 is 7°, and the taper angle of the second inner taper surface of the outer centering die 2 is also 7°. The inner centering die 1 and the outer centering die 2 are both made of hard alloy material. The hard alloy material is a prior art, and thus no further description is given herein. The first axial through hole of the inner centering die 1 is further provided with an inner circular segment coaxially arranged at the adjacent position of the first taper large end of the first inner taper surface. The inner diameter of the inner circular segment is greater than the diameter of the first inner taper surface at the first taper large end, forming a step structure. This structure design facilitates the installation of the thin-walled annular workpiece 3.

[0041] The thin-walled annular workpiece 3 is specifically a thin-walled wrapping tube of a permanent magnet motor magnetic steel, which can also be referred to as an alloy sleeve, and is applied to the manufacturing process of a permanent magnet synchronous rotor. In order to avoid overheat shrinkage fitting of the permanent magnet synchronous rotor, the inner and outer diameters of the thin-walled annular workpiece 3 need to be controlled within a specified range.

[0042] The thin-walled wrapping tube of the permanent magnet motor magnetic steel of the present embodiment is a kind of adjustable universal tooling, which is suitable for high-precision machining of the inner circle of the thin-walled annular workpiece 3 and can form a specific process flow. Through the cooperation of the jig and a high-precision internal grinding machine, the inner circle precision of the thin-walled annular workpiece 3 is controlled, so that the thin-walled annular workpiece 3 and the outer diameter of the rotor magnetic steel form a proper interference fit with a precision of-0.043 to-0.035.

[0043] After finish machining, the thin-walled annular workpiece 3 can be heated by 230 degrees (less than 300 degrees is non-overheat shrinkage fitting, which generally has no effect on the magnetic steel), and then the heat shrinkage fitting process is performed to achieve the installation of the specified interference amount and ensure that the magnetic material is not damaged during the installation process.

[0044] In the specific operation process, the inner centering die 1 and the outer centering die 2 can move axially, and the moving position of the axial movement can be adjusted by the adjusting screw. After the thin-walled annular workpiece 3 is placed in the inner hole of the inner centering die 1 and the outer centering die 2, the adjusting screw is adjusted so that the outer circle of the thin-walled annular workpiece 3 is concentrically sleeved with the inner centering die 1 and the outer centering die 2. At this time, the inner centering die 1 and the outer centering die 2 are clamped on the general inner circle grinding head and the tailstock, and the inner circle of the thin-walled annular workpiece 3 after grinding reaches the height of the outer circle.

[0045] The above-described specific embodiments further specifically describe the technical problems, technical solutions and beneficial effects solved by the utility model, and it should be understood that the above-described specific embodiments are merely specific embodiments of the utility model and are not used to limit the utility model, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A permanent magnet motor magnetic steel thin-wall wrapping tube inner circle grinding clamp, characterized in that, The application relates to a permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp which comprises the following parts: an inner centering die (1), a circumferential outer surface of the inner centering die (1) is provided with an outer circle positioning surface, the inner centering die (1) is provided with a first axial through hole, an inner wall of the first axial through hole is formed with a first inner taper surface, and the first inner taper surface is provided with a first taper surface small end and a first taper surface large end; an outer centering die (2), the outer centering die (2) is provided with a second axial through hole, an inner wall of the second axial through hole is sequentially provided with an inner matching surface adapted to be slidably matched with the outer circle positioning surface of the inner centering die (1) and a second inner taper surface adjacent to the inner matching surface in the axial direction, and the second inner taper surface is provided with a second taper surface small end and a second taper surface large end; wherein, when the outer circle positioning surface of the inner centering die (1) is slidably matched with the inner matching surface of the outer centering die (2), the first taper surface large end of the first inner taper surface is oppositely arranged with the second taper surface large end of the second inner taper surface, and a taper space adapted to clamp a thin-wall annular workpiece (3) is formed.

2. The permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp according to claim 1, wherein the inner centering die (1) is provided with a circular truncated cone structure extending radially outward, and at least one screw through slot is arranged on the circular truncated cone structure. One end of the outer centering die (2) is provided with a matching surface adapted to be matched with the circular truncated cone structure of the inner centering die (1), and a threaded hole corresponding to the position of the screw through slot is arranged on the matching surface of the outer centering die (2).

3. The permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp according to claim 2, wherein four screw through slots are arranged on the circular truncated cone structure of the inner centering die (1), and four threaded holes corresponding to the positions of the screw through slots are arranged on the matching surface of the outer centering die (2).

4. The permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp according to claim 1, wherein the taper angle of the first inner taper surface of the inner centering die (1) is 2-12 degrees.

5. The permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp according to claim 1, wherein the taper angle of the second inner taper surface of the outer centering die (2) is the same as that of the first inner taper surface of the inner centering die (1).

6. The permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp according to claim 1, wherein the inner centering die (1) and the outer centering die (2) are both made of hard alloy material.

7. The permanent magnet motor magnetic steel thin-wall wrapping pipe inner circle grinding clamp according to claim 1, wherein the first axial through hole of the inner centering die (1) is further provided with a coaxially arranged inner circle segment, the inner circle segment is arranged at a position adjacent to the first taper surface large end of the first inner taper surface, and the inner diameter of the inner circle segment is greater than the diameter of the first inner taper surface at the first taper surface large end. ​ ​ ​ ​ ​ ​

Images