Novel connection structure of magnetic ring and rotor shaft

Abstract

The utility model discloses a novel connection structure of a magnetic ring and a rotor shaft, which comprises the magnetic ring sleeved on the rotor shaft, the outer ring of the magnetic ring is sleeved with a plastic bushing, the inner wall of the plastic bushing is in interference fit with the outer ring of the magnetic ring, and the outer wall of the plastic bushing is in interference fit with the rotor shaft; an elastic buffering structure is arranged on the inner wall of the plastic lining and comprises wavy protrusions distributed on the inner ring of the plastic lining at equal intervals, and a circumferential positioning structure is arranged between the plastic lining and the magnetic ring and comprises an anti-rotation block arranged on the inner side of the plastic lining. According to the utility model, the structure design is scientific and reasonable, the inner wall of the plastic bushing is in interference fit with the outer ring of the magnetic ring, and the outer wall is in interference fit with the rotor shaft, so that radial tension borne by the magnetic ring is converted into compression force, and the problem of magnetic ring cracking caused by direct interference assembly is solved; the wavy protrusions on the inner ring of the plastic lining are adopted, assembly stress is absorbed through elastic deformation, and the situation that the brittle material of the magnetic ring generates microcracks due to stress concentration is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of equipment, concretely to a novel magnetic ring and rotor shaft connecting structure. BACKGROUND

[0002] Because the brushless motor needs to control the rotating position of the rotor accurately, a magnetic ring needs to be assembled on the rotor shaft to sense the position of the magnetic ring through a Hall sensor or other position sensor. The current design is generally realized through interference assembly of the rotor magnetic ring and the rotor shaft or an inner sleeve metal bushing. The former is prone to cracking when bearing the expansion of the rotor shaft because of the poor plasticity of the magnetic ring, resulting in unstable mass production. The latter will cause the increase of part and mold costs because the newly added metal bushing needs to be injection molded with the magnetic ring. Therefore, the utility model provides a novel magnetic ring and rotor shaft connecting structure. SUMMARY

[0003] The utility model discloses a novel magnetic ring and rotor shaft connecting structure, which aims to solve the problems in the background art.

[0004] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a novel magnetic ring and rotor shaft connecting structure, comprising a magnetic ring sleeved on a rotor shaft, a plastic bushing sleeved on the outer ring of the magnetic ring, and an interference fit between the inner wall of the plastic bushing and the outer ring of the magnetic ring and an interference fit between the outer wall of the plastic bushing and the rotor shaft.

[0005] The inner wall of the plastic bushing is provided with an elastic buffer structure, which comprises wave-shaped protrusions distributed equidistantly on the inner ring of the plastic bushing, and a circumferential positioning structure is arranged between the plastic bushing and the magnetic ring, which comprises an anti-rotation block arranged on the inner side of the plastic bushing, an anti-rotation groove is formed in the outer ring of the magnetic ring, the anti-rotation block is correspondingly clamped in the anti-rotation groove, and a plurality of expansion grooves are formed in the outer side of the plastic bushing.

[0006] In the above-mentioned scheme, the inner side of each plastic bushing is provided with a convex block and a concave groove for concave-convex clamping.

[0007] In the above-mentioned scheme, a sealing ring is arranged at the contact position of the plastic bushing and the rotor shaft.

[0008] In the above-mentioned scheme, the interference amount between the plastic bushing and the magnetic ring is 0.05-0.08 mm, and the interference amount between the plastic bushing and the rotor shaft is 0.12-0.15 mm.

[0009] In the above-mentioned scheme, the protrusion height of the wave-shaped protrusion is 0.2-0.5 mm, and the distance between adjacent protrusions is 1-2 mm.

[0010] In the above-mentioned scheme, the plastic bushing is a glass fiber reinforced PEEK bushing, and the outer wall of the plastic bushing is provided with an axial flow guide groove.

[0011] In the above scheme, the expansion groove width is 0.1-0.3mm, and the depth is 50%-70% of the bushing wall thickness.

[0012] Compared with the prior art, the novel magnetic ring and rotor shaft connecting structure has the advantages that the structure is simple and reasonable, and has strong practicability, the radial tension of the magnetic ring is converted into compression force through interference fit between the inner wall of the plastic bushing and the outer ring of the magnetic ring and interference fit between the outer wall and the rotor shaft, the problem of cracking of the magnetic ring caused by direct interference fit is solved, the wave-shaped protrusions of the inner ring of the plastic bushing are elastically deformed to absorb assembly stress, the local pressure peak is reduced, and micro-cracks of the brittle material of the magnetic ring caused by stress concentration are avoided, the gap fit between the anti-rotation block on the inner side of the plastic bushing and the anti-rotation groove of the outer ring of the magnetic ring allows fine adjustment while achieving circumferential positioning, the assembly cumulative error is eliminated, and the torque transmission efficiency is high. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The utility model discloses a structure schematic diagram.

[0014] Figure 2 The utility model discloses a structure schematic diagram.

[0015] Figure 3 The utility model discloses a structure schematic diagram.

[0016] Figure 4 The utility model discloses a structure schematic diagram. Figure 2 The utility model discloses a structure schematic diagram.

[0017] In the figure: 1, rotor shaft 11, magnetic ring 12, plastic bushing 13, protruding block 14, recess 15, wave-shaped protrusion 16, expansion groove 17, anti-rotation block 18, anti-rotation groove 19, sealing ring. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0019] Please refer to Figures 1-3 The utility model provides a kind of technical solutions: a kind of novel magnetic ring and rotor shaft connecting structure, including the magnetic ring 11 of being set on rotor shaft 1, the outer ring of the magnetic ring 11 is equipped with plastic bushing 12, the inner wall of the plastic bushing 12 is interference fit with the outer ring of the magnetic ring 11, and its outer wall is interference fit with rotor shaft 1;

[0020] The inner wall of the plastic bushing 12 is provided with an elastic buffering structure, which includes wave-shaped protrusions 15 distributed equidistantly on the inner ring of the plastic bushing 12. The plastic bushing 12 and the magnetic ring 11 are respectively provided with circumferential positioning structures, which include anti-rotation blocks 17 arranged on the inner side of the plastic bushing 12. The outer ring of the magnetic ring 11 is provided with anti-rotation grooves 18, and the anti-rotation blocks 17 are correspondingly clamped in the anti-rotation grooves 18. A plurality of expansion grooves 16 are arranged on the outer side of the plastic bushing 12.

[0021] Through the gap cooperation between the anti-rotation blocks 17 on the inner side of the plastic bushing and the anti-rotation grooves 18 on the outer ring of the magnetic ring, the circumferential positioning is realized while allowing ±0.5° fine adjustment, eliminating the cumulative error of assembly, and making the torque transmission efficiency high.

[0022] In the above scheme, the inner side of each of the two plastic bushings 12 is respectively provided with a convex block 13 and a concave groove 14 that are engaged in a concave-convex manner. The interlocking design of the convex blocks 13 and the concave grooves 14 on the inner side of the two plastic bushings improves the axial connection stiffness by 30%, effectively preventing the axial movement of the bushing during high-speed operation.

[0023] In the above scheme, the contact position of the plastic bushing 12 and the rotor shaft 1 is provided with a sealing ring 19. The sealing ring 19 at the contact position of the rotor shaft blocks the infiltration of lubricating oil into the working area of the magnetic ring and compensates for the micro-gap of the interference fit, so that the system can stably operate under the IP67 protection level.

[0024] In the above scheme, the interference amount of the plastic bushing 12 and the magnetic ring 11 is 0.05-0.08mm, and the interference amount of the plastic bushing 12 and the rotor shaft 1 is 0.12-0.15mm. Through the interference fit between the inner wall of the plastic bushing 12 and the outer ring of the magnetic ring 11 and the interference fit between the outer wall and the rotor shaft 1, the radial tension borne by the magnetic ring is converted into compression force, solving the problem of magnetic ring cracking caused by direct interference assembly.

[0025] In the above scheme, the protrusion height of the wave-shaped protrusion 15 is 0.2-0.5mm, and the distance between adjacent protrusions is 1-2mm. The wave-shaped protrusions 15 on the inner ring of the plastic bushing absorb assembly stress through elastic deformation, reduce local pressure peak value, and avoid the generation of micro-cracks in brittle materials of the magnetic ring due to stress concentration.

[0026] In the above scheme, the plastic bushing 12 is made of glass fiber reinforced PEEK bushing, and the outer wall of the plastic bushing 12 is provided with an axial flow guide groove. The use of 20%-30% glass fiber reinforced PEEK material in cooperation with the axial flow guide groove on the outer wall can discharge air to avoid air bubble stress during press fitting, thereby improving the assembly yield and reducing the mold cost.

[0027] In the scheme, the width of the expansion groove 16 is 0.1-0.3mm, and the depth is 50%-70% of the bushing wall thickness. The plurality of expansion grooves 16 formed along the outside of the plastic bushing can absorb the thermal expansion difference between the plastic and the metal shaft by groove deformation when the temperature changes, and the axial displacement is controlled to be less than 0.01mm.

[0028] Working principle:

[0029] The connecting structure of the novel magnetic ring and the rotor shaft converts the radial tension of the magnetic ring into compression force through the interference fit between the inner wall of the plastic bushing 12 and the outer ring of the magnetic ring 11 and the interference fit between the outer wall and the rotor shaft 1, solving the problem of magnetic ring cracking caused by direct interference assembly. The interlocking design of the two plastic bushing inner side protrusions 13 and the grooves 14 increases the axial connection stiffness by 30%, effectively preventing the axial movement of the bushing during high-speed operation. The wave-shaped protrusions 15 on the inner ring of the plastic bushing absorb assembly stress through elastic deformation, reducing the local pressure peak value and avoiding the generation of micro-cracks in the brittle material of the magnetic ring due to stress concentration. The sealing ring 19 at the contact position of the rotor shaft blocks the infiltration of lubricating oil into the working area of the magnetic ring and compensates for the interference fit gap, allowing the system to operate stably under IP67 protection level.

[0030] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is defined by the appended claims and their equivalents.

Claims

1. A novel connection structure of a magnetic ring and a rotor shaft, comprising a magnetic ring (11) sleeved on a rotor shaft (1), characterized in that: The magnetic ring (11) is sleeved with a plastic bushing (12), the inner wall of the plastic bushing (12) is in interference fit with the outer ring of the magnetic ring (11), and the outer wall is in interference fit with the rotor shaft (1); The inner wall of the plastic bushing (12) is provided with an elastic buffering structure, the elastic buffering structure includes wave-shaped protrusions (15) distributed equidistantly on the inner ring of the plastic bushing (12), circumferential positioning structures are respectively arranged between the plastic bushing (12) and the magnetic ring (11), the circumferential positioning structures include anti-rotation blocks (17) arranged on the inner side of the plastic bushing (12), the outer ring of the magnetic ring (11) is provided with anti-rotation grooves (18), the anti-rotation blocks (17) are correspondingly clamped in the anti-rotation grooves (18), and a plurality of expansion grooves (16) are arranged on the outer side of the plastic bushing (12).

2. The connection structure of a new type magnetic ring and a rotor shaft according to claim 1, characterized in that: The inner sides of the two plastic bushings (12) are respectively provided with convex blocks (13) and concave grooves (14) in concave-convex engagement.

3. The connection structure of a novel magnetic ring and a rotor shaft according to claim 1, characterized in that: The contact position of the plastic bushing (12) and the rotor shaft (1) is provided with a sealing ring (19).

4. The connection structure of a novel magnetic ring and a rotor shaft according to claim 1, characterized in that: The interference amount of the plastic bushing (12) and the magnetic ring (11) is 0.05-0.08mm, and the interference amount of the plastic bushing (12) and the rotor shaft (1) is 0.12-0.15mm.

5. The connection structure of a novel magnetic ring and a rotor shaft according to claim 1, characterized in that: The protrusion height of the wave-shaped protrusion (15) is 0.2-0.5mm, and the interval between adjacent protrusions is 1-2mm.

6. The connection structure of a novel magnetic ring and a rotor shaft according to claim 1, characterized in that: The plastic bushing (12) adopts a glass fiber reinforced PEEK bushing, and the outer wall of the plastic bushing (12) is provided with an axial flow guide groove.

7. The connection structure of a novel magnetic ring and a rotor shaft according to claim 1, characterized in that: The width of the expansion groove (16) is 0.1-0.3mm, and the depth is 50%-70% of the bushing wall thickness.

Images