An assembly aid
By designing an assembly tool consisting of a top ring, a base, and bolts, the problem of gaps during stator core assembly was solved, achieving stable compaction and efficient assembly of the stator core, improving the assembly success rate and reducing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- YIZHONG GRP (HEILONGJIANG) HEAVY IND CO LTD
- Filing Date
- 2025-06-24
- Publication Date
- 2026-08-04
AI Technical Summary
In existing technologies, gaps are prone to appear in the stator core during assembly, leading to assembly failure, especially after cooling.
An assembly tooling is used, including a top ring, a base, a first bolt, and a second bolt. The top ring is slidably fitted onto the flywheel journal. There is a gap between the base and the top ring. The second bolt connects the base and the flywheel journal. The first bolt axially tightens the top ring to form a stable mechanical structure, ensuring that the tightening force is transmitted vertically along the axial direction and preventing deflection or vibration.
This assembly tool ensures seamless cooling of the stator core, improves assembly quality and success rate, reduces costs, and solves the problem of sourcing stator cores and inspection rings.
Smart Images
Figure CN224596335U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of assembly technology, and more specifically, to an assembly aid. Background Technology
[0002] Pre-tightening during assembly is an important step in the assembly process. For example, when assembling stator cores at both ends of the flywheel rotor in an energy storage project, these stator cores are generally made of 0.1mm thick steel sheets welded together, with a total thickness of up to 80mm. They are fitted onto the journal using a hot fitting method. After assembly, the stator cores must be pressed firmly to prevent gaps from appearing, otherwise the assembly will fail.
[0003] In related technologies, one method is to use axially fixed auxiliary fixtures for clamping and compaction, but gaps are very likely to appear after the stator core cools down. Utility Model Content
[0004] The problem this invention aims to solve is how to improve the assembly success rate of stator core assembly pre-tightening.
[0005] To address the aforementioned problems, this utility model provides an assembly aid for pre-tightening the stator core when assembling it onto the flywheel journal. The assembly aid includes a top ring, a base, a first bolt, and a second bolt. The top ring is configured to slidably fit onto the flywheel journal, with one end of the top ring abutting against the outer end face of the stator core. The base is positioned at the other end of the top ring, with a gap between them. The second bolt connects the base and the flywheel journal. The first bolt is mounted on the base and axially tightens the top ring.
[0006] Optionally, one end of the top ring is provided with an annular end face, which abuts against the outer end face of the stator core, and the area of the annular end face is greater than or equal to the area of the outer end face of the stator core.
[0007] Optionally, the top ring is sleeved around the flywheel journal, and the inner circumferential surface of the top ring is provided with a first step and a second step in sequence away from the annular end face. The flywheel journal is provided with a threaded section and a smooth section. The first step corresponds to the threaded section, and the second step corresponds to the connection between the threaded section and the smooth section.
[0008] Optionally, the inner circumferential surface of the top ring is clearance-fitted with the smooth section.
[0009] Optionally, the corners of the second step portion and the corners at the connection between the threaded section and the smooth section are each provided with chamfers.
[0010] Optionally, the base is configured to be disposed opposite to the end face of the flywheel journal, and the second bolt connects the base and the flywheel journal along the axial direction of the flywheel journal.
[0011] Optionally, the second bolt is also equipped with an anti-loosening washer and / or threadlocker.
[0012] Optionally, the first bolt is threaded onto the base, one end of the first bolt is used to abut against the other end of the top ring, and the other end of the first bolt protrudes from the base.
[0013] Optionally, the first bolts are provided in multiple portions and are evenly distributed along the circumference of the top ring.
[0014] Optionally, the major diameter of the thread of the second bolt is larger than the major diameter of the thread of the first bolt.
[0015] The beneficial effects of this assembly fixture are as follows: the top ring is slidably fitted onto the flywheel journal, with one end of the top ring abutting against the outer end face of the stator core. A base is positioned at the other end of the top ring, with a gap between them. A second bolt connects the base and the flywheel journal. Through the cooperation of the second bolt, the base, and the flywheel journal, the base serves as the axial positioning reference for the entire assembly fixture, providing stable support for subsequent axial adjustment of the top ring. The gap between the base and the top ring, along with the abutting against the outer end face of the stator core at one end of the top ring, allows the top ring to be slidably adjusted. The base fits tightly against the outer end face of the stator core, ensuring that the clamping force is transmitted vertically along the flywheel journal axis. Therefore, after the base is fixed by the second bolt, the circumferential and radial degrees of freedom of the base are completely restricted, leaving only the axial movement degree of freedom of the top ring (adjusted by the first bolt). This forms a stable mechanical structure of "fixed base - adjustable top ring", preventing the top ring from deflecting or vibrating during the clamping process. It ensures that the clamping force can be continuously applied during the cooling process of the stator core, ensuring that there are no gaps between the stator cores, thereby eliminating assembly gaps, ensuring that the stator core is compacted, completing the assembly, and improving the assembly quality and success rate. Attached Figure Description
[0016] Figure 1 This diagram illustrates the structure of the flywheel and auxiliary device in accordance with the present invention. Figure 2 It shows Figure 1 A magnified view of a portion of the image; Figure 3 A schematic diagram of the assembly aid in an embodiment of this utility model is shown. Figure 1 ; Figure 4 A schematic diagram of the assembly aid in an embodiment of this utility model is shown. Figure 2 ; Figure 5 A schematic diagram of the assembly aid in an embodiment of this utility model is shown. Figure 3 ; Figure 6 A schematic diagram of the top ring structure in an embodiment of this utility model is shown; Figure 7 A schematic diagram of the base in an embodiment of this utility model is shown.
[0017] Explanation of reference numerals in the attached figures: 1. Flywheel; 2. Stator core; 3. Top ring; 31. First step; 32. Second step; 33. Inner circumferential surface; 4. Base; 5. First bolt; 6. Second bolt; 7. Flywheel journal; 71. Threaded section; 72. Smooth section; 8. Detection ring; 9. Center threaded hole; 10. First threaded hole; 11. Second threaded hole. Detailed Implementation
[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.
[0019] In the attached diagram, the Z-axis represents the vertical direction, i.e., up and down, with the positive direction of the Z-axis representing up and the negative direction representing down. The X-axis represents the horizontal direction and is designated as the front and back position, with the positive direction of the X-axis representing the front and the negative direction representing the back. The Y-axis represents the left and right position, with the positive direction of the Y-axis representing the left and the negative direction representing the right. It should be noted that the aforementioned representations of the Z, Y, and X axes are merely for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0020] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or illustrative embodiment of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.
[0021] Reference Figure 1 , Figure 2 and Figure 3As shown in the figure, this utility model embodiment proposes an assembly aid for pre-tightening the stator core 2 when it is assembled onto the flywheel journal 7. The assembly aid includes a top ring 3, a base 4, a first bolt 5, and a second bolt 6. The top ring 3 is configured to be slidably fitted onto the flywheel journal 7, and one end of the top ring 3 abuts against the end face of the stator core 2. The base 4 is used to be disposed at the other end of the top ring 3, and a gap is provided between the two. The second bolt 6 is used to connect the base 4 and the flywheel journal 7. The first bolt 5 is installed on the base 4 and is used to axially tighten the top ring 3.
[0022] Specifically, in Figure 1 In the flywheel 1, two stator cores 2 are respectively mounted on the flywheel journals 7 at both ends. A detection ring 8 is provided between the two stator cores 2. The stator core 2 is generally made of steel sheets of about 0.1mm thickness welded together, with a total thickness of about 80mm (about 800 steel sheets). After the stator core 2 and the detection ring 8 are assembled on the flywheel journals 7 by heat fitting, they are pre-tightened by the assembly fixture in this embodiment. The specific steps are as follows: Step 1: Fit the top ring 3 onto the flywheel journal 7, ensuring that the assembly is smooth and there is a moderate amount of axial movement; Step 2: Screw the second bolt 6 into the flywheel journal 7 (the flywheel journal 7 may have a corresponding threaded hole) and tighten it; Step 3: Screw the first bolt 5 into the base 4 and let its end pass through the base 4. Tighten the top ring 3 by pressing the end of the first bolt 5, so that the stator core 2 and the detection ring 8 are pressed together. Step 4: Tighten the first bolt 5 once every preset time interval to ensure that the top ring 3 is compacted. Only after the stator core 2 and the detection ring 8 have completely cooled to room temperature and are seamless can the assembly fixture be removed.
[0023] In this embodiment, the top ring 3 is slidably fitted onto the flywheel journal 7, with one end of the top ring 3 abutting against the outer end face of the stator core 2. The base 4 is positioned at the other end of the top ring 3, with a gap between them. The second bolt 6 connects the base 4 and the flywheel journal 7. Through the cooperation of the second bolt 6, the base 4, and the flywheel journal 7, the base 4 becomes the axial positioning reference for the entire assembly fixture, providing stable support for subsequent axial adjustment of the top ring 3. With the gap between the base 4 and the top ring 3, and the abutting of one end of the top ring 3 against the outer end face of the stator core 2, the top ring 3 can be slidably fitted onto the flywheel journal 7. The outer end face of the stator core 2 fits tightly, ensuring that the clamping force is transmitted vertically along the axis of the flywheel journal 7. Therefore, when the base 4 is fixed by the second bolt 6, the circumferential and radial degrees of freedom of the base 4 are completely restricted, leaving only the axial movement degree of freedom of the top ring 3 (adjusted by the first bolt 5), forming a stable mechanical structure of "fixed base 4 - adjustable top ring 3". This prevents the top ring 3 from deflecting or vibrating during the clamping process, ensuring that the clamping force can be continuously applied during the cooling process of the stator core 2, ensuring that there are no gaps between the stator cores 2, thereby eliminating assembly gaps, ensuring that the stator core 2 is compacted, completing the assembly, and improving the assembly quality and success rate.
[0024] In addition, by using the above assembly tools, the problem of outsourcing the assembly of the stator core 2 and the detection ring 8, which was previously only processed by the flywheel rotor, can be solved, thus reducing costs.
[0025] like Figure 2 As shown, in an optional embodiment of the present invention, one end of the top ring 3 is provided with an annular end face, which abuts against the outer end face of the stator core 2, and the area of the annular end face is greater than or equal to the area of the outer end face of the stator core 2.
[0026] Specifically, the annular end face is the side of the top ring 3 that contacts the stator core 2. For example, Figure 6 The annular end face with a radius of 22mm directly abuts against the outer end face of the top ring 3. Its end face flatness is ≤0.1mm, which evenly transmits the tightening force of the first bolt 5 (multiple bolts can be symmetrically arranged) to avoid local stress concentration that could cause deformation of the stator core 2. When the area of the annular end face is larger than the area of the outer end face of the stator core 2, the annular radius of its annular end face should extend outward to avoid it abutting against the flywheel journal 7, thereby ensuring smooth tightening.
[0027] In practice, the flywheel journals 7 at both ends of the flywheel 1 are heat-fitted with two stator cores 2 and a detection ring 8, with an interference fit of 0.15mm. The stator cores are made of B20T1500 cold-rolled steel plate, each piece is 80mm thick, and consists of 400 layers of 0.2mm thick steel plates. The detection ring 8 is 30mm thick and made of stainless steel.
[0028] like Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, in an optional embodiment of this utility model, the top ring 3 is sleeved around the flywheel journal 7. The inner circumferential surface 33 of the top ring 3 has a first stepped portion 31 and a second stepped portion 32 sequentially arranged away from the annular end face. The flywheel journal 7 has a threaded section 71 and a smooth section 72. The first stepped portion 31 corresponds to the threaded section 71, and the second stepped portion 32 corresponds to the connection point between the threaded section 71 and the smooth section 72.
[0029] Specifically, by setting the first step portion 31 and the second step portion 32 on the top ring 3, radial centering and anti-deviation can be performed on the flywheel journal 7. The second step portion 32 and its rear end cooperate with the smooth section 72 to form a radial centering reference. The first step portion 31 ( Figure 6 The coaxiality tolerance of the portion (173mm→134mm in the example) is ≤0.2mm, ensuring the coaxiality of the top ring 3 on the threaded section 71 and avoiding eccentricity causing uneven load (excessive force on one side leading to jamming) when the first bolt 5 is tightened. After the base 4 is fixed, the coaxiality error between its inner ring and the flywheel journal 7 is ≤0.5mm, ensuring that the first step 31 inside the top ring 3 can accurately fit into the smooth section 72 of the flywheel journal 7, avoiding interference between the second step 32 and the threaded section 71 due to the offset of the base 4, indirectly protecting the surface accuracy of the flywheel journal 7, and ensuring the smooth axial movement of the top ring 3 (without jamming).
[0030] exist Figure 6 In the middle, on the top ring 3, the inner circumferential surface 33 with an inner diameter of φ126mm corresponds to the smooth section 72 of the flywheel journal 7, and the inner wall of the second step 32 forms a radial clearance with the outer circle of the journal; the threaded section 71 on the flywheel journal 7 is provided with an M130 thread, and the top ring 3 is designed with a second step 32 of φ134*10 (forming a stop) to prevent the threads from being damaged during assembly, and to ensure that the threads will not be damaged when the top ring 3 is pressed forward (in the negative direction of the y axis) to the limit position.
[0031] like Figure 1 , Figure 2 ,and Figure 6 As shown, in an optional embodiment of this utility model, the inner circumferential surface 33 of the top ring 3 is in clearance fit with the smooth section 72.
[0032] Specifically, a clearance fit is formed between the inner circumferential surface 33 of the top ring 3 and the outer circle of the smooth section of the flywheel journal 7 to ensure that there is no interference resistance when the top ring 3 is fitted in, and the radial wobble is ≤0.1mm. This avoids jamming due to excessive tightness or skewing due to excessive looseness, and ensures the control accuracy of the mating surface.
[0033] like Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, in an optional embodiment of the present invention, the corners of the second step portion 32 and the corners at the connection between the threaded section 71 and the smooth section 72 are respectively provided with chamfers.
[0034] Specifically, the corners of the second step portion 32 are rounded, that is, the inner hole edge of the second step portion 32 (the annular boss end face corresponding to the smooth section 72) is provided with a radius of 2mm rounded corner, and the corners of the connection between the threaded section 71 of the flywheel journal 7 and the smooth section 72 are chamfered (not shown in the figure) to eliminate sharp edge contact during assembly, reduce frictional resistance, and further improve the smoothness of fitting.
[0035] like Figure 2 As shown, in an optional embodiment of the present invention, the base 4 is configured to be opposite to the end face of the flywheel journal 7, and the second bolt 6 connects the base 4 and the flywheel journal 7 along the axial direction of the flywheel journal 7.
[0036] Specifically, for example, the first bolt 5 is configured as an M24 bolt and the second bolt 6 is configured as an M42 bolt. The M42 bolt is selected mainly because the flywheel journal 7 has a pre-drilled M42 threaded hole, which does not require additional processing and reduces the adaptation cost. After the top ring 3 is assembled, the six M24 threads are screwed into the base 4, the M42 bolt is placed into the φ44 hole, and after aligning the threaded hole on the flywheel journal 7, the M42 threaded hole is screwed in, and the base 4 can be assembled. The first bolt 5 cooperates with the base 4 through the second threaded hole 11, and the second bolt 6 cooperates with the base 4 through the first threaded hole 10 and is screwed into the center threaded hole 9 on the flywheel journal 7.
[0037] The base 4 is fixed to the flywheel journal 7 by an M42 thread, and the top ring 3 is abutted to the base 4 by the first bolt 5, forming a two-stage structure of "coarse positioning (the second bolt 6 is configured as an M42 bolt) + fine tightening (the first bolt 5 is configured as an M24 bolt)". M24 is a commonly used secondary bolt under the M42 specification. The difference between the two pitches (M42 pitch is usually 4.5mm, M24 pitch is 3mm) is reasonable to avoid excessive processing difficulty. In addition, the effective length of the first bolt 5 must cover the connection thickness of the base 4 and the top ring 3 (the effective length is greater than the sum of the thicknesses of the base 4 and the top ring 3). The length of the commonly used M24 bolt can meet the installation requirements, ensure the thread engagement depth, and avoid stripping.
[0038] After the base 4 is fixed by the second bolt 6, the axial adjustment of the top ring 3 (via the M24 bolt) can accurately transmit the tightening force on the rigid chain of "base 4 → top ring 3 → stator core 2". The tightening torque of the second bolt 6 can be achieved in one go by a hydraulic torque wrench, ensuring that the base 4 is installed in place and avoiding subsequent tightening failure due to the loosening of the base 4. This forms a logical closed loop of "first fixing the base 4, then dynamically tightening" with the process step of "tightening the first bolt 5 every preset time interval (e.g., 10 minutes)".
[0039] As an optional embodiment of this utility model, the second bolt 6 is also equipped with an anti-loosening washer and / or thread-locking adhesive.
[0040] Specifically, the second bolt 6 serves as a key connection for fixing the base 4. It can be used with anti-loosening washers (located on the outer end face of the base 4) or thread-locking adhesive (not shown in the figure). Its large-diameter thread has a better natural anti-loosening effect (greater pitch and stable coefficient of friction) than small-diameter threads, ensuring that the top ring 3 of the auxiliary tool and the base 4 maintain reliable connection after multiple disassemblies and reassemblies, which meets the engineering requirement of "reusable auxiliary tool".
[0041] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, in an optional embodiment of the present invention, the first bolt 5 is threadedly installed on the base 4, one end of the first bolt 5 is used to abut against the other end of the top ring 3, and the other end of the first bolt 5 protrudes from the base 4.
[0042] Specifically, the first bolt 5 is installed from the outer end of the base 4 inward and abuts against the other end of the top ring 3. The first bolt 5 makes the top ring 3 fit tightly against the end face of the stator core 2, so as to prevent the base 4 from loosening or shifting due to the axial thrust of the second bolt 6 during the tightening process, and ensure that the tightening force is transmitted vertically along the axial direction of the flywheel journal 7.
[0043] like Figure 3 , Figure 4 , Figure 5 As shown, in an optional embodiment of the present invention, the first bolt 5 is provided in multiple portions and is evenly distributed along the circumference of the top ring 3.
[0044] Specifically, the first bolts 5 are evenly distributed to ensure that the axial load is applied evenly to the top ring 3 and that the load is evenly distributed. For example, 6 M24 bolts are evenly distributed around the circumference of the base 4 and evenly correspond to the circumference of the top ring 3, so that the tightening force can be evenly transmitted to the stator core 2 and local stress concentration can be avoided. The bolt spacing design must meet the requirements of structural compactness. When 6 holes are arranged around the φ134mm second step, the hole spacing of the M24 bolts is reasonable, which ensures both strength and ease of processing.
[0045] like Figure 2 , Figure 3 As shown, in an optional embodiment of this utility model, the major diameter of the thread of the second bolt 6 is larger than the major diameter of the thread of the first bolt 5.
[0046] Specifically, the second bolt 6 is the center bolt, and its load-bearing capacity is generally required to be stronger than that of the first bolt 5. For example, when the 6-M24 bolt (first bolt 5) applies an axial tightening force to the stator core 2 through the top ring 3, the M42 bolt (second bolt 6) needs to withstand the same magnitude of reverse tension in order to complete the mechanical balance support and facilitate the compaction of the stator core 2.
[0047] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the present invention.
[0048] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.
Claims
1. An assembly aid, characterized in that The assembly pre-tightening tool is used for assembling the stator core (2) onto the flywheel journal (7). The assembly tool includes a top ring (3), a base (4), a first bolt (5), and a second bolt (6). The top ring (3) is configured to be slidably fitted onto the flywheel journal (7), and one end of the top ring (3) abuts against the end face of the stator core (2). The base (4) is used to be set at the other end of the top ring (3) and there is a gap between the two. The second bolt (6) is used to connect the base (4) and the flywheel journal (7). The first bolt (5) is installed on the base (4) and is used to axially tighten the top ring (3).
2. The assembly aid of claim 1, wherein, One end of the top ring (3) is provided with an annular end face, which abuts against the outer end face of the stator core (2), and the area of the annular end face is greater than or equal to the area of the outer end face of the stator core (2).
3. The assembly aid of claim 2, wherein, The top ring (3) is sleeved around the flywheel journal (7). The inner circumferential surface (33) of the top ring (3) is provided with a first step (31) and a second step (32) in sequence away from the annular end face. The flywheel journal (7) is provided with a threaded section (71) and a smooth section (72). The first step (31) corresponds to the threaded section (71), and the second step (32) corresponds to the connection between the threaded section (71) and the smooth section (72).
4. The assembly aid of claim 3, wherein, The inner circumferential surface (33) of the top ring (3) is in clearance fit with the smooth section (72).
5. The assembly aid according to claim 3 or 4, characterized in that The corners of the second step (32) and the corners at the connection between the threaded section (71) and the smooth section (72) are all chamfered.
6. The assembly aid according to any one of claims 1-4, wherein, The base (4) is arranged opposite to the end face of the flywheel journal (7), and the second bolt (6) connects the base (4) and the flywheel journal (7) along the axial direction of the flywheel journal (7).
7. The assembly aid according to any one of claims 1-4, wherein, The second bolt (6) is also equipped with an anti-loosening washer and / or thread sealant.
8. The assembly fixture according to any one of claims 1-4, characterized in that, The first bolt (5) is threaded onto the base (4), one end of the first bolt (5) is used to abut against the other end of the top ring (3), and the other end of the first bolt (5) protrudes from the base (4).
9. The assembly fixture according to claim 8, characterized in that, The first bolt (5) has multiple bolts and is evenly distributed along the circumference of the top ring (3).
10. The assembly fixture according to claim 9, characterized in that, The major diameter of the thread of the second bolt (6) is greater than that of the thread of the first bolt (5).