A new type of inclined support arm rotor bracket structure

Abstract

The present invention relates to the technical field of hydrogenerator manufacturing, and provides a novel inclined support arm type rotor bracket structure, which includes: a central ring plate, a cylindrical wall, inclined support arm members and steel pipes. Cylindrical walls are coaxially arranged on both sides of the central ring plate respectively to form a cylindrical structure. One ends of a plurality of inclined support arm members are arranged on the outer side of the cylindrical wall, and the angle formed by each inclined support arm member and the tangential direction of the cylindrical wall is 30°-80°. The other ends of adjacent inclined support arm members are connected by steel pipes, solving the problems of low structural strength, poor operation stability, easy fracture of welding points and short service life, and having the effects of high structural strength, good operation stability and long service life.

Description

Technical Field

[0001] The present invention relates to the technical field of the manufacture of hydro-generators, and particularly relates to a novel inclined support arm type rotor bracket structure. Background Art

[0002] In large and medium-sized vertical hydro-generators, the rotor bracket is an intermediate component that connects the magnetic yoke and the rotating shaft into one body. Factors such as structural dimensions, mechanical strength and stiffness requirements, ventilation patterns, as well as manufacturing processes, installation and transportation have a direct impact on the structural form of the rotor bracket.

[0003] In the rotor structure of small and medium-sized horizontal bulb tubular hydro-generators, there is no magnetic yoke lamination. The rotor poles are fixed to the magnetic yoke ring of the rotor bracket through tensioning screws. Among them, the rotor bracket is a welded structure, and the magnetic yoke ring is a whole cylindrical structure. Over the years, our factory has been accustomed to using a radial rib and web type rotor bracket, and its performance has been verified in the operation practices of units in multiple power stations.

[0004] However, for large bulb tubular hydro-generators (with an outer diameter of stator punching sheets above 7560 mm, a core length above 1400 mm, and a rated capacity above 35,000 KVA), the rotor structure adopts a structure with magnetic yoke lamination similar to that of vertical units (but not exactly the same as vertical units). Therefore, on the basis of drawing on advanced foreign design concepts and combining with the manufacturing experience of our factory, an inclined support arm type rotor bracket structure applicable to large bulb tubular hydro-generators is proposed. This structure has a similar inclined support arm type rotor bracket structure to that of large vertical units, but also has structural characteristics applicable to tubular units.

[0005] Existing rotor bracket structures mostly adopt straight support arm rotor brackets, resulting in poor concentricity of the unit and poor uniformity of the air gap between the stator and the rotor, and cannot provide safety and stability for large-capacity bulb tubular hydro-generator sets under various operating conditions. There are problems such as low structural strength, poor operating stability, easy fracture of welding points, and short service life. Summary of the Invention

[0006] In order to solve the above technical problems, the present invention relates to a novel inclined support arm type rotor bracket structure.

[0007] A novel rotor bracket structure with inclined support arms, comprising: a central ring plate, a cylindrical wall, inclined support arm members and steel pipes. On both sides of the central ring plate, cylindrical walls are coaxially arranged respectively to form a cylindrical structure. One ends of multiple inclined support arm members are arranged on the outer side of the cylindrical wall, and the acute angle formed by each inclined support arm member and the tangential direction of the cylindrical wall is 30° - 80°. The other ends of adjacent inclined support arm members are connected by steel pipes. The inclined support arm members include: inner rib plates, outer rib plates and vertical rib plates. One end of an inner rib plate is arranged on the outer side of the cylindrical wall, and the acute angle formed by each inner rib plate and the tangential direction of the cylindrical wall is 72°. The other end of the inner rib plate is connected to one end of the outer rib plate, and the other end of the outer rib plate is connected to the vertical rib plate. Adjacent vertical rib plates are connected by steel pipes.

[0008] A chute is arranged at the other end of the inner rib plate, and a slider is arranged at one end of the outer rib plate. The slider is matched with the chute and connected by screws. Reinforcing ribs are arranged on the side wall of the inner rib plate.

[0009] Furthermore, a main shaft is installed on the central ring plate.

[0010] Furthermore, the inner rib plate is fixed to the cylindrical wall by welding, and the outer rib plate is fixed to the vertical rib plate by welding.

[0011] Furthermore, the outer rib plate is a trapezoidal plate.

[0012] The beneficial effects of the present invention are as follows:

[0013] The present invention provides a novel rotor bracket structure with inclined support arms. Compared with the straight support arm rotor bracket structure, the inclined support arm rotor bracket structure does not affect the axial stiffness of the unit, but increases the radial flexibility. Its function is to convert the radial force of the rotor bracket structure into a tangential force, so that the concentricity of the unit is better, and the uniformity of the air gap between the stator and the rotor is better, significantly improving the safety and stability of large-capacity bulb tubular hydro-generator units under various operating conditions. The present invention adopts a new structure of chute-slider cooperation and fixation by screws, improving the connection strength. Compared with the welding method in the prior art, it avoids the occurrence of solder joint fracture, and has the effects of high structural strength, good operation stability and long service life. Description of the Drawings

[0014] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a schematic structural diagram of the present invention;

[0016] Figure 2 Schematic diagram of the local section of the present invention;

[0017] Figure 3 Enlarged schematic diagram of the local section of the present invention;

[0018] Wherein:

[0019] 1. Central ring plate; 2. Cylinder wall; 3. Inclined support arm member;

[0020] 4. Steel pipe; 31. Inner rib plate; 32. Outer rib plate;

[0021] 33. Vertical rib plate; 34. Slide groove; 35. Reinforcing rib;

[0022] 36. Slide block. Specific implementation mode

[0023] Next, in combination with the accompanying drawings in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0024] It should be noted that the installation methods and technical terms mentioned in the present invention are all well-known technical terms in the technical field, so no further explanation will be made. In addition, the same reference numerals are used for the same components, but this does not affect nor should it constitute an accurate understanding of the technical solution by those skilled in the art.

[0025] Embodiment 1:

[0026] First, according to the design requirements such as the inner diameter size of the rotor yoke and its installation form, the spindle size and its shape, etc., determine the structural dimensions of each component of the rotor bracket.

[0027] The present invention relates to a novel inclined support arm type rotor bracket structure, comprising: a central ring plate (1), a cylindrical wall (2), inclined support arm members (3) and steel pipes (4). On both sides of the central ring plate (1), cylindrical walls (2) are coaxially arranged respectively to form a cylindrical structure. One end of a plurality of inclined support arm members (3) is arranged on the outer side of the cylindrical wall (2), and the angle formed by each inclined support arm member (3) and the tangential direction of the cylindrical wall (2) is an acute angle of 30° to 80°. The other ends of adjacent inclined support arm members (3) are connected by steel pipes (4). The inclined support arm members (3) include: inner rib plates (31), outer rib plates (32), and vertical rib plates (33). One end of the inner rib plate (31) is arranged on the outer side of the cylindrical wall (2), and the angle formed by each inner rib plate (31) and the tangential direction of the cylindrical wall (2) is an acute angle of 72°. In the design, it is necessary to ensure the coaxiality of the vertical rib plate (33) relative to the axis center line. The other end of the inner rib plate (31) is connected to one end of the outer rib plate (32), and the other end of the outer rib plate (32) is connected to the vertical rib plate (33). Adjacent vertical rib plates (33) are connected by steel pipes (4). Screw holes for fixing the rotor yoke are machined on the vertical rib plate (33), and various machining for installing with the main shaft is completed on the central ring plate (1). All machined surfaces are coated with antirust grease. In the manufacturing factory, after the rotor bracket is machined, a static balance test is carried out. When the unbalanced moment is greater than 6.18 Kg.m, counterweights are required, and the counterweights are welded on the inner rib plate (31) and the outer rib plate (32), but attention should be paid to avoiding the installation position of the excitation leads. The steel pipe (4) is a support tool for the welding, machining and transportation of the rotor bracket and is removed after the lamination on the construction site.

[0028] A sliding groove (34) is arranged at the other end of the inner rib plate (31), and a sliding block (36) is arranged at one end of the outer rib plate (32). The sliding block (36) is matched with the sliding groove (34) and connected by screws. Reinforcing ribs (35) are arranged at intervals on the side wall of the inner rib plate (31), and the reinforcing ribs are used to prevent the sliding block (36) and the sliding groove (34) from being deformed by force.

[0029] A main shaft is installed on the central ring plate (1).

[0030] The inner rib plate (31) is fixed to the cylindrical wall (2) by welding, and the outer rib plate (32) is fixed to the vertical rib plate (33) by welding. All weld seams are polished to a smooth transition. When polishing the weld seam between the vertical rib plate (33) and the outer rib plate (32), the solder inside the groove is not removed. The surface roughness Ra of the polished weld seam is 6.3, and annealing is carried out after welding.

[0031] The outer rib plate (32) is a trapezoidal plate.

[0032] Such a setting solves the problems of low structural strength, poor operating stability, easy fracture of welding points, and short service life. By adopting an inclined support arm rotor bracket structure, without affecting the axial stiffness of the unit, the radial flexibility is increased, and the risk of shrinkage cracking of the welding points can be controlled. At the parts where the welding points are prone to cracking, a new sliding groove and slider combination and screw connection method are adopted to replace the original welding connection method, thus avoiding the occurrence of shrinkage and cracking of the welding points, and achieving the effects of high structural strength, good operating stability, and long service life.

[0033] Basic principle:

[0034] When two annular parts undergo concentric expansion, the inclined members all twist in the direction of the least resistance, and the two annular parts also twist around their respective centers. However, when the deformation movement or twist of one annular part is out of sync with that of the other annular part, the inclined members will tend to deform in the direction of the greatest resistance. Theory and practice have proved that when the rotor connects two rings with straight members, there is a risk of shrinkage and cracking in welding, but the inclined members can control this risk because the welding shrinkage stress is balanced by the rotating central body and the inclined members, and moreover, by adopting a new connection method, the connection strength is greatly improved.

[0035] For those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed invention.

[0036] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent replacements, and improvements made to the above embodiments based on the technical essence of the present invention should be included in the protection scope of the technical solution of the present invention.

Claims

1. A novel inclined support arm type rotor bracket structure, comprising: a central ring plate (1), a barrel wall (2), inclined support arm members (3) and steel pipes (4). The barrel walls (2) are coaxially arranged on both sides of the central ring plate (1) respectively to form a cylindrical structure. One ends of a plurality of inclined support arm members (3) are arranged on the outer side of the barrel wall (2), and the angle formed by each inclined support arm member (3) and the tangent direction of the barrel wall (2) is an acute angle of 30° to 80°. The other ends of adjacent inclined support arm members (3) are connected by steel pipes (4). The inclined support arm member (3) comprises an inner rib plate (31), an outer rib plate (32) and a vertical rib plate (33). One end of the inner rib plate (31) is arranged on the outer side of the barrel wall (2), and the angle formed by each inner rib plate (31) and the tangent direction of the barrel wall (2) is an acute angle of 72°. The other end of the inner rib plate (31) is connected to one end of the outer rib plate (32). The other end of the outer rib plate (32) is connected to the vertical rib plate (33). Adjacent vertical rib plates (33) are connected by steel pipes (4). It is characterized in that, a chute (34) is arranged at the other end of the inner rib plate (31), a slider (36) is arranged at one end of the outer rib plate (32), the slider (36) is matched with the chute (34) and connected by screws, and reinforcing ribs (35) are arranged on the side wall of the inner rib plate (31); a main shaft is installed on the central ring plate (1); the inner rib plate (31) and the barrel wall (2) are fixed by welding, and the outer rib plate (32) and the vertical rib plate (33) are fixed by welding.

2. A novel inclined support arm type rotor bracket structure according to claim 1, characterized in that, the outer rib plate (32) is a trapezoidal plate.

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