Pressing assembly of a stator core

Abstract

The application relates to the technical field of a generator stator, and discloses a press-fitting assembly of a stator core, which comprises a machine base, a tensioning piece, a core, a pressing plate and a pressing finger, the upper and lower ends of the core are provided with the pressing fingers, the pressing plate is abutted on the pressing fingers and is fastened on the machine base through the tensioning piece, the pressing fingers and the pressing plate adopt a separated structure, and the pressing finger at any end is fixed on the core. The application is suitable for a back-carrying structure and a core-penetrating structure, and solves the problem of one-side pressing failure caused by insufficient installation precision.

Description

Technical Field

[0001] This invention relates to the field of generator stator assembly technology, and more specifically to a stator core press-fit assembly. Background Technology

[0002] A generator is a device that converts mechanical energy into electrical energy, and it mainly consists of two parts: a stator and a rotor. The stator core is the core magnetic circuit component of the generator stator. To reduce eddy current losses, it is usually made of laminated structures composed of layers of insulating thin silicon steel sheets. If the core is not tightly pressed, it will generate vibration, noise, and even damage the laminated insulation layer under the influence of the magnetic field, leading to the core burning out. Therefore, the core pressing process is crucial.

[0003] Currently, stator core pressing is mainly divided into two structures: "back-mounted" and "through-core". In existing technology, both structures generally adopt the method of welding and fixing multiple pressing fingers to a toothed pressure plate, and then transmitting the pressing force to the end of the core through the pressure plate.

[0004] Chinese patent document CN109088488A discloses a method for installing a floating stator core of a hydro-generator. The hydro-generator is equipped with a stator floating core positioning and tightening device, which includes a base ring plate connected to the stator frame; a lower toothed pressure plate installed on the base ring plate; an upper toothed pressure plate; stator core plates stacked between the upper and lower toothed pressure plates; a stator pressure plate located on the side of the upper toothed pressure plate away from the stator core plates; and a through-bolt for fastening; and two or more stator core plates connected to the stator frame. The stator has a double dovetail support plate; two or more double dovetail ribs; the through-core screw passes through the stator pressure plate, upper tooth pressure plate, stacked stator cores, lower tooth pressure plate, and frame ring plate; the through-core screw is fitted with an insulating sleeve; the two ends of the through-core screw are respectively provided with a first locking nut and a second locking nut; a butterfly spring fitted on the through-core screw is also provided between the first locking nut and the stator pressure plate; an insulating washer fitted on the through-core screw is also provided between the first locking nut and the butterfly spring; the stator pressure plate is connected to the stator frame through a stator core adjusting screw.

[0005] The existing technology has the following shortcomings: the horizontal installation accuracy of the pressure plate directly determines the contact effect between the pressure finger and the iron core. If the parallelism between the pressure plate and the end face of the iron core is insufficient after installation, the clamping force will be concentrated on the inner or outer side of the iron core, resulting in a lack of effective clamping on the other side, forming a "one-sided inadequate clamping" phenomenon, with one side tilting upwards. This not only requires a very high level of technical skill from the installers, but also, during long-term operation of the unit, factors such as thermal expansion of the iron core and creep of the tie rod will further exacerbate the clamping force deviation, seriously affecting the durability and reliability of the clamping effect. The above problems are common in both the back-mounted and through-core pressing structures. Summary of the Invention

[0006] To simultaneously solve the technical problem of low horizontal installation accuracy leading to one-sided upward tilting in both back-mounted and through-core types, this invention provides a stator core press-fit assembly, including a base, a tensioning member, a core, a pressure plate, and pressure fingers. The pressure fingers are provided at both the upper and lower ends of the core. The pressure plate abuts against the pressure fingers and is fastened to the base by the tensioning member. The key feature is that the pressure fingers and the pressure plate adopt a separate structure, and the pressure finger at either end is fixed to the core.

[0007] In order to decouple the pressure finger from the pressure plate, the pressure plate and pressure finger provided at the upper end of the iron core are an upper pressure plate and an upper pressure finger. A groove is provided between the upper pressure plate and the upper pressure finger. The groove is used to limit the loading area, avoid the clamping force from being biased to one side, and ensure a good clamping effect.

[0008] Preferably, the groove is located on the upper pressure plate.

[0009] To ensure effective compression on both sides of the iron core, a second groove is provided between the upper pressure finger and the iron core. The second groove is used to distribute the load.

[0010] Preferably, the second groove is located on the upper pressing finger.

[0011] Preferably, the pressure plate and pressure finger provided at the lower end of the iron core are a lower pressure plate and a lower pressure finger. The lower pressure finger abuts against the lower end face of the iron core, and the lower pressure plate and the lower pressure finger are fixedly connected to each other to achieve lower end clamping.

[0012] To provide axial clamping force to the pressure plate, pressure fingers, and iron core, and to maintain a long-term locked position, a set screw is provided on the upper pressure plate. The set screw is located on one side of the machine base and abuts against the machine base.

[0013] The present invention has the following beneficial effects: 1. In existing technologies, the parallelism of the pressure plate and the pressure fingers cannot be guaranteed. The clamping force of the pressure plate tends to be biased towards the inner or outer side of the iron core, resulting in a lack of effective clamping force on the other side. The pressure fingers may also tilt upwards relative to the iron core. This invention designs the pressure fingers and pressure plate as independent components, ensuring the freedom of the pressure fingers is decoupled from the pressure plate. This avoids the pressure plate's horizontality affecting the installation angle of the pressure fingers, ensuring good contact between the pressure fingers and the iron core. One side of the pressure fingers is directly fixed to the end of the iron core, no longer constrained by the horizontality error of the pressure plate. During on-site installation, even if the pressure plate is slightly tilted, each pressure finger can still maintain good contact with the end face of the iron core. This solves the problem of insufficient clamping force on one side due to insufficient installation accuracy, greatly reducing installation accuracy requirements, improving installation efficiency, reducing installation costs, and minimizing the impact of clamping force bias on the clamping effect caused by factors such as thermal expansion of the iron core and creep of the tie rod during long-term use. Ordinary workers can operate this system.

[0014] 2. The structure of this invention is not dependent on a specific pressing method. Whether it is a back-mounted structure (the clamping force is transmitted from the outside of the iron core) or a through-core structure (the tie rod passes through the yoke of the iron core), this component can be used directly without changing the separation relationship between the pressing fingers and the pressing plate, and without making additional modifications to the frame or iron core. This invention can simultaneously cover two mainstream stator iron core pressing methods. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of Embodiment 1 of the stator core press-fit assembly of the present invention; Figure 2 This is a schematic diagram of Embodiment 2 of the stator core press-fit assembly of the present invention. Detailed Implementation

[0016] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings of the instruction manual include: base 1, set screw 2, upper pressure plate 3, upper pressure finger 4, lower pressure finger 5, lower pressure plate 6, tensioning component 7, iron core 8, groove one 9, groove two 10.

[0017] Example 1 like Figure 1 As shown, a stator core press-fit assembly is suitable for back-mounted stator core press-fitting. It includes a base 1, a set screw 2, an upper pressure plate 3, upper pressure fingers 4, lower pressure fingers 5, a lower pressure plate 6, a tensioning member 7, and a core 8. The core 8 is made of multiple layers of insulated silicon steel sheets. Multiple upper pressure fingers 4 are evenly arranged circumferentially on the upper end face of the core 8. The upper pressure fingers 4 are directly welded and fixed to the carbon steel plate on the outer side of the end of the core 8. The upper pressure fingers 4 are in close contact with the end face of the core 8.

[0018] The upper pressure plate 3 is located above the upper pressure finger 4 and is a separate component independent of the upper pressure finger 4.

[0019] The bottom surface of the upper pressure plate 3 is provided with a groove 9, which matches the top shape of the upper pressure finger 4 and only contacts the upper pressure finger 4 at the non-groove part of the end, thus defining the loading area and avoiding pressure deviation.

[0020] The bottom surface of the upper pressing finger 4 that contacts the iron core 8 is provided with a second groove 10. The second groove 10 is set along the width direction of the upper pressing finger 4 to evenly distribute the pressing force to the inner and outer sides of the iron core 8.

[0021] Multiple sets of set screws 2 are installed on the base 1. The ends of the set screws 2 abut against the upper end face of the base 1. By screwing the set screws 2, an axial clamping force is applied. The pressure is evenly transmitted to the upper end face of the iron core 8 through the upper pressure plate 3 and the upper pressure finger 4.

[0022] The lower end of the iron core 8 is provided with a pressing finger 5 and a pressing plate 6. The pressing finger 5 abuts against the lower end surface of the iron core 8, and the pressing plate 6 abuts against the pressing finger 5 to achieve lower end clamping. For ease of manufacturing and installation, the pressing plate 6 is part of the base 1.

[0023] The tensioning member 7 connects the upper and lower pressure plates, providing overall locking force. During assembly, the lower pressure plate 6 and the lower pressure finger 4 are first welded and fixed together. Then, the iron core 8 is stacked on the lower pressure finger 4, and the upper pressure finger 4 is welded and fixed to the upper end face of the iron core 8. Next, the upper pressure plate 3 is placed so that the groove 9 is accurately aligned with the upper pressure finger 4. Finally, the set screw 2 and the tensioning member 7 are tightened to complete the uniform pressing of the iron core 8.

[0024] Example 2 like Figure 2 As shown, a stator core pressing assembly is applicable to the pressing of through-core stator cores. The structure is basically the same as that of Embodiment 1, except for the pressing force application method.

[0025] In this embodiment, the set screw 2 structure is eliminated, and a through-core tensioning member is used as the main clamping component. The tensioning member 7 passes through the interior of the iron core 8, and its two ends are respectively connected to the upper pressure plate 3 and the lower pressure plate 6. Axial tension is provided by tightening the nuts at both ends of the tensioning member 7.

[0026] The upper pressure finger 4 remains separate from the upper pressure plate 3, and is welded and fixed to the upper end of the iron core 8. The upper pressure plate 3 has a groove 9, and the upper pressure finger 4 has a groove 10. The pressure transmission and load distribution principle is the same as in Embodiment 1, which can ensure that the inner and outer sides of the iron core 8 are pressed synchronously and evenly.

[0027] This embodiment does not require the cooperation of the base 1 and the set screw 2, and is suitable for core-type press fitting scenarios. It can also solve the problems of high installation accuracy requirements, uneven clamping force, and poor long-term clamping effect.

[0028] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A stator core press-fit assembly, comprising a frame (1), a tensioning member (7), a core (8), a pressure plate, and pressure fingers, wherein the pressure fingers are provided at both the upper and lower ends of the core (8), and the pressure plate abuts against the pressure fingers and is fastened to the frame (1) by the tensioning member (7), characterized in that, The pressure finger and the pressure plate adopt a separate structure, and the pressure finger at either end is fixed on the iron core (8).

2. The stator core press-fit assembly according to claim 1, characterized in that: The pressure plate and pressure finger provided at the upper end of the iron core (8) are an upper pressure plate (3) and an upper pressure finger (4), and a groove (9) is provided between the upper pressure plate (3) and the upper pressure finger (4).

3. The stator core press-fit assembly according to claim 2, characterized in that: The groove 1 (9) is located on the upper pressure plate (3).

4. The stator core press-fit assembly according to claim 3, characterized in that: A groove 2 (10) is provided between the upper pressing finger (4) and the iron core (8).

5. The stator core press-fit assembly according to claim 4, characterized in that: The second groove (10) is located on the upper pressing finger (4).

6. The stator core press-fit assembly according to claim 5, characterized in that: The pressure plate and pressure finger provided at the lower end of the iron core (8) are a lower pressure plate (6) and a lower pressure finger (5). The lower pressure finger (5) abuts against the lower end face of the iron core (8). The lower pressure plate (6) and the lower pressure finger (5) are fixedly connected to each other to achieve lower end pressing.

7. The stator core press-fit assembly according to claim 6, characterized in that: The upper pressure plate (3) is provided with a set screw (2), which is located on one side of the machine base (1) and abuts against the machine base (1).

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