A cast aluminum rotor positioning dummy shaft with variable tolerances

Abstract

The utility model belongs to the technical field of motor production equipment relates to a variable tolerance cast aluminium rotor positioning dummy axle, include: dummy axle body, the dummy axle body is equipped with the central hole, the central hole is the taper hole of the diameter from below to above shrink, the dummy axle body one side is equipped with the axial opening of the through dummy axle body, the adjustment round table, the adjustment round table and the taper of dummy axle body central hole are same, and the adjustment round table is inserted into the central hole by the bottom of dummy axle body and forms the combined dummy axle, wherein, can pass through the adjustment round table of axial movement, drive the elastic deformation of dummy axle body at the axial opening occurs to change its outer diameter. The utility model provides variable tolerance cast aluminium rotor positioning dummy axle can improve rotor cast aluminium, rotor lamination speed, avoids the wear and tear of dummy axle simultaneously, guarantees the straightness of cast aluminium rotor.

Description

Technical Field

[0001] This utility model belongs to the technical field of motor production equipment, and relates to a dummy shaft for positioning a cast aluminum rotor with variable tolerance. Background Technology

[0002] In the manufacturing process of motor rotors, rotor laminations are stacked and then cast into guide bars using aluminum casting. During this process, a dummy shaft is used to position and support the rotor laminations to ensure the coaxiality and straightness of the cast rotor. Conventional dummy shafts have fixed diameter tolerances. Due to these tolerances, the laminations are difficult to install properly during lamination stacking, and the dummy shaft is prone to wear over time, resulting in poor straightness of the finished cast aluminum rotor.

[0003] Chinese utility model patent CN221929564U (publication date: 2024-10-29) discloses a flexible dummy shaft for a cast aluminum rotor, including a shaft body. The shaft body has an installation cavity along its axial direction. A flexible component is disposed in the installation cavity. The flexible component includes a tensioning block and a flexible element disposed between the tensioning blocks. The shaft body has an installation hole corresponding to the tensioning block along its radial direction. The installation hole communicates with the installation cavity. The tensioning block is located in the installation hole and slides with the installation hole along the radial direction of the shaft body.

[0004] The aforementioned flexible dummy shaft can ensure that the shaft body can adapt to the changes in the inner diameter of the cast aluminum rotor caused by thermal expansion and contraction during die casting and cooling. However, its structure is complex, requiring the machining of precision structures such as mounting cavities, multiple mounting holes, and slide rails. It also requires the separate manufacture of multiple tensioning blocks and flexible parts, making the assembly process cumbersome. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a dummy shaft for positioning cast aluminum rotors with variable tolerances. This can increase the rotor lamination speed during the casting process while avoiding wear on the dummy shaft and ensuring the straightness of the cast aluminum rotor.

[0006] To solve the above-mentioned technical problems, the objective of this utility model is achieved through the following technical solution: A tolerance-variable cast aluminum rotor positioning dummy shaft, comprising: The dummy shaft body has a central hole, which is a tapered hole with a tapered diameter that narrows from bottom to top, and an axial opening that penetrates the dummy shaft body is provided on one side. An adjusting frustum has the same taper as the central hole of the dummy shaft body. The adjusting frustum is inserted into the central hole from the bottom of the dummy shaft body to form a combined dummy shaft. The outer diameter of the dummy shaft body can be changed by axially moving the adjusting frustum, causing the dummy shaft body to undergo elastic deformation at the axial opening.

[0007] In the above-mentioned variable tolerance cast aluminum rotor positioning dummy shaft, the dummy shaft body is provided with a positioning groove that cooperates with the lamination, and the axial opening is opened at the center position of the side wall of the dummy shaft body corresponding to the positioning groove.

[0008] In the above-mentioned tolerance-variable cast aluminum rotor positioning dummy shaft, the dummy shaft body and the adjusting frustum have the same axial dimension. In the initial state, the upper and lower end faces of the adjusting frustum are flush with the dummy shaft body. The initial state refers to the state in which the dummy shaft body is not deformed by the squeezing of the adjusting frustum.

[0009] In the aforementioned tolerance-variable cast aluminum rotor positioning dummy shaft, an axially extending blind groove is provided on the inner wall of the dummy shaft body with the axial opening opposite to it.

[0010] In the aforementioned tolerance-variable cast aluminum rotor positioning dummy shaft, the blind groove is further provided in the upper half of the dummy shaft body, and its groove depth gradually increases from bottom to top.

[0011] In the above-mentioned tolerance-variable cast aluminum rotor positioning dummy shaft, the upper end of the outer wall of the dummy shaft body is provided with a guide cone surface, and the lower end is provided with a limiting protrusion ring; the guide cone surface forms a guiding structure when the lamination is installed, and the limiting protrusion ring forms a limiting structure after the lamination is installed.

[0012] In the aforementioned dummy shaft for positioning a cast aluminum rotor with variable tolerance, the two ends of the adjusting frustum are provided with blind holes for engaging with the adjusting tool.

[0013] In the above-mentioned variable tolerance cast aluminum rotor positioning dummy shaft, the taper of the center hole and the adjusting frustum is 1:30-1:40; preferably, the taper of the center hole and the adjusting frustum is 1:35.

[0014] Compared with the prior art, this utility model has the following advantages: 1. This utility model provides a dummy shaft for positioning a cast aluminum rotor with variable tolerance. Through the adjustable outer diameter of the dummy shaft, it can actively and precisely match the inner hole size of the rotor laminations. During lamination stacking, the operator can first adjust the dummy shaft to the optimal diameter, allowing each lamination to be easily and smoothly fitted into the dummy shaft and installed in place. This eliminates installation resistance caused by excessively tight tolerances, thereby significantly improving the efficiency and smoothness of the lamination stacking operation.

[0015] 2. This invention effectively avoids dummy shaft wear and ensures the straightness of the cast aluminum rotor: First, the adjustable mechanism of this invention itself compensates for wear. When the dummy shaft experiences normal wear over long-term use, resulting in a decrease in outer diameter, a slight upward adjustment of the internal adjusting frustum is sufficient to restore it to its original standard size, thereby greatly extending the service life of the dummy shaft and avoiding frequent replacements due to rapid wear. Second, through this continuous precision assurance, all rotor laminations are precisely positioned and supported on the same straight line throughout the entire aluminum casting process, fundamentally solving problems such as bending and misalignment of the cast aluminum rotor caused by dummy shaft wear or dimensional discrepancies. Ultimately, this ensures that the cast aluminum rotor forms a high-precision straight line, improving product quality. Attached Figure Description

[0016] Figure 1 This is a perspective view of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is an axial sectional view of the present invention; Figure 4 This is an exploded view of this utility model; Reference numerals: 1. Dummy shaft body; 11. Center hole; 12. Axial opening; 13. Positioning groove; 14. Blind groove; 15. Guide cone surface; 16. Limiting protrusion ring; 2. Adjusting frustum; 21. Center blind hole. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-4 : A tolerance-variable cast aluminum rotor positioning dummy shaft, comprising: The dummy shaft body 1 has a central hole 11, which is a tapered hole with a reduced diameter from bottom to top. An axial opening 12 is provided on one side of the dummy shaft body 1. Adjusting frustum 2, the adjusting frustum 2 has the same taper as the center hole 11 of the dummy shaft body 1, and the adjusting frustum 2 is inserted into the center hole 11 from the bottom of the dummy shaft body 1 to form a combined dummy shaft; The outer diameter of the dummy shaft body 1 can be changed by axially moving the adjusting frustum 2 to cause elastic deformation at the axial opening 12.

[0018] In this embodiment, the dummy shaft body 1 and the adjusting frustum 2 have the same axial dimension. In the initial state (the initial state refers to the state where the dummy shaft body 1 is not deformed by the adjusting frustum 2), the upper and lower end faces of the adjusting frustum 2 are flush with the dummy shaft body 1. At this time, the outer diameter of the dummy shaft has a minimum value. According to the inner hole tolerance of the rotor laminations and the wear condition of the dummy shaft, the adjusting frustum 2 is pushed to a predetermined position by a tool, and the outer diameter of the dummy shaft is actively adjusted to the optimal size. The rotor laminations are then sequentially fitted onto the dummy shaft. Since the size of the dummy shaft has been precisely set, the lamination process is smooth and the positioning is accurate. After the aluminum casting is completed, the adjusting frustum 2 is gently tapped downwards to remove it. The outer diameter of the dummy shaft shrinks, and the cast aluminum rotor can be easily removed from the dummy shaft.

[0019] The aforementioned dummy shaft body 1 is provided with a positioning groove 13 that cooperates with the lamination, and the axial opening 12 is opened at the center of the side wall of the dummy shaft body 1 corresponding to the positioning groove 13. By placing the axial opening 12 at the weakest and most easily deformed part of the dummy shaft body 1, the uniformity and predictability of the change in the outer diameter of the dummy shaft can be ensured, thereby controlling the final size more accurately.

[0020] An axially extending blind groove 14 is provided on the inner wall of the dummy shaft body 1 opposite to the aforementioned axial opening 12. Furthermore, the blind groove 14 is located in the upper half of the dummy shaft body 1, and its depth gradually increases from bottom to top. By adding the blind groove 14, uneven deformation of the dummy shaft body 1 caused by the difference in wall thickness between the upper and lower parts can be avoided.

[0021] The upper end of the outer wall of the aforementioned dummy shaft body 1 is provided with a guide cone surface 15, and the lower end is provided with a limiting protrusion ring 16; the guide cone surface 15 forms a guide structure when the lamination is installed, and the limiting protrusion ring 16 forms a limiting structure after the lamination is installed.

[0022] To facilitate the application of force and precise adjustment of its axial position, the two ends of the adjustment frustum 2 are provided with tip blind holes 21 that cooperate with the adjustment tool.

[0023] In this embodiment, the taper of the central hole 11 and the adjusting frustum 2 is 1:30-1:40; preferably, the taper of the central hole 11 and the adjusting frustum 2 is 1:35.

[0024] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection of the present utility model.

Claims

1. A dummy shaft for positioning a cast aluminum rotor with variable tolerance, characterized in that, include: The dummy shaft body (1) has a central hole (11), which is a tapered hole with a reduced diameter from bottom to top. An axial opening (12) penetrating the dummy shaft body (1) is provided on one side of the dummy shaft body (1). Adjustment frustum (2), the adjustment frustum (2) has the same taper as the center hole (11) of the dummy shaft body (1), and the adjustment frustum (2) is inserted into the center hole (11) from the bottom of the dummy shaft body (1) to form a combined dummy shaft; The outer diameter of the dummy shaft body (1) can be changed by axially moving the adjusting frustum (2) to cause elastic deformation at the axial opening (12).

2. The tolerance-variable cast aluminum rotor positioning dummy shaft according to claim 1, characterized in that, The dummy shaft body (1) is provided with a positioning groove (13) that cooperates with the punch, and the axial opening (12) is opened at the center position of the side wall of the dummy shaft body (1) corresponding to the positioning groove (13).

3. The variable tolerance cast aluminum rotor positioning dummy shaft according to claim 1, characterized in that, The dummy shaft body (1) and the adjusting frustum (2) have the same axial dimensions. In the initial state, the upper and lower end faces of the adjusting frustum (2) are flush with the dummy shaft body (1).

4. The tolerance-variable cast aluminum rotor positioning dummy shaft according to claim 1, characterized in that, An axially extending blind groove (14) is provided on the inner wall of the dummy shaft body (1) opposite to the axial opening (12).

5. A tolerance-variable cast aluminum rotor positioning dummy shaft according to claim 4, characterized in that, The blind groove (14) is located in the upper half of the dummy shaft body (1), and its groove depth gradually increases from bottom to top.

6. A dummy shaft for positioning a cast aluminum rotor with variable tolerance according to claim 1, characterized in that, The upper end of the outer wall of the dummy shaft body (1) is provided with a guide cone surface (15), and the lower end is provided with a limiting protrusion ring (16).

7. A dummy shaft for positioning a cast aluminum rotor with variable tolerance according to claim 1, characterized in that, The adjusting frustum (2) has a top blind hole (21) at both ends of its shaft center that cooperates with the adjusting tool.

8. A dummy shaft for positioning a cast aluminum rotor with variable tolerance according to claim 1, characterized in that, The taper of the central hole (11) and the adjusting frustum (2) is 1:30-1:40.

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