A generator rotor with stiffness compensation

Abstract

The present invention discloses a generator rotor with stiffness compensation, belonging to the technical field of steam turbine generators. The rotor body is provided with axially variable cross-section ventilation auxiliary grooves, and the groove depth configuration is divided into two forms: either a groove section combination of an outer straight groove section, an inclined groove section, and an inner straight groove section, or a stepped groove section structure that decreases step by step from the outside to the inside along the axial direction; the surface of the large teeth is processed with crescent grooves corresponding to the ventilation auxiliary groove sections, and the depth of the crescent grooves is distributed according to the position of the ventilation auxiliary groove sections. The depth of the crescent grooves decreases as the depth of the ventilation auxiliary grooves decreases, and the crescent grooves corresponding to the outer groove sections are deeper than those corresponding to the inner groove sections. The present invention effectively solves the technical problem of the large difference in stiffness between large and small teeth at different cross-sectional positions of the rotor in the prior art, meets the actual demand for stiffness balance between large and small teeth, and is particularly suitable for the field of high-performance generators with strict requirements on stiffness uniformity.

Description

Technical Field

[0001] The invention belongs to the technical field of steam turbine generators, and in particular relates to a stiffness-compensated generator rotor. Background Art

[0002] The turbine generator rotor is an important component of the turbine generator and is responsible for generating a rotating magnetic field. The two-pole turbine generator rotor is an asymmetric cross-section rotor, and its structure includes the following: Figure 6 The small teeth 2 (i.e., the wire-inlaying portion) and the large teeth 3 (i.e., the non-wire-inlaying portion) shown in the figure have different stiffness. If the large rotor teeth are stiffer than the small teeth 2, the degree of bending will change twice with each rotation of the rotor, causing harmonic vibration. If the large rotor teeth are stiffer than the small teeth, the degree of bending will also change twice with each rotation, causing harmonic vibration. This vibration is difficult to reduce or eliminate through static and dynamic balancing techniques in the later stages of production. If the design is not appropriate, it may cause severe vibration of the shaft or bearing seat, and even cause the unit vibration to exceed the standard.

[0003] In view of this situation, large generators usually adopt a design of slotting the large teeth to make the stiffness of the small teeth and large teeth on the rotor body nearly equal. Figure 7 As shown in the figure, a common slotting design is to machine axial slots 4 throughout the entire axial length of the large teeth 3 of the rotor body 1. This design is effective in balancing the stiffness difference between the small teeth 2 and the large teeth 3. However, its machining process is slightly complicated and can lead to a loss of magnetic conductive area on the pole face, which has a significant impact on the magnetic flux density of the rotor yoke.

[0004] Another example is the patent document with the announcement number CN202309262U, which discloses two types of crescent groove structures: one is an old-fashioned crescent groove structure with a semi-arc bottom on the large teeth of the rotor body of the steam turbine generator; the other is a flat-bottomed straight crescent groove structure with a flat-bottomed straight crescent groove. Regardless of whether it is a semi-arc or flat-bottomed straight crescent groove, they are arranged at a certain spacing, number and depth to form a series of single crescent groove structures of the same specifications and shapes. For rotors with full radial ventilation or radial-axial ventilation, such as Figure 7-9 As shown, the bottom of the rotor's wire-embedded slot 9 is usually provided with ventilation slots 5, which are of various types, including stepped slots, oblique slots and straight slots 8. Figure 9 In the straight auxiliary groove structure shown, the groove bottom is flat and the groove depth is designed to be constant, forming a straight groove shape with a constant cross-section. In this case, using crescent grooves or axial grooves of the same specifications and shape can effectively achieve the required rigidity balance between the large and small tooth structures.

[0005] However, the skewed secondary slots, due to their differentiated configuration of alternating straight and skewed slots, form a variable cross-section with varying slot depths. Stepped secondary slots, on the other hand, also form a variable cross-section through the differentiated configuration of multiple stepped slot segments. Consequently, the aforementioned crescent slots or axial slots are unsuitable for ventilation secondary slots with this variable cross-section structure. If crescent slots or axial slots of the same specifications and shape were still used for adaptation, it would be difficult to achieve an effective stiffness balance between the large and small teeth at different cross-sectional locations of the rotor.

[0006] In view of this situation, there is an urgent need to design an innovative generator rotor to meet the actual needs of balancing the stiffness of large and small teeth, thereby improving the overall stability and reliability of the rotor operation, ensuring that it can significantly reduce vibration during operation, extend the service life of the unit, and improve power generation efficiency. Summary of the Invention

[0007] The purpose of the present invention is to solve the above-mentioned problems existing in the prior art and provide a generator rotor with stiffness compensation, which effectively solves the technical problem in the prior art that the stiffness difference between large teeth and small teeth at different cross-sectional positions of the rotor is large, meets the actual demand for stiffness balance between large and small teeth, and improves the overall stability and reliability of the rotor operation.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] The present invention provides a stiffness-compensated generator rotor, comprising a rotor body, the rotor body being provided with ventilation sub-grooves of variable cross-section, the ventilation sub-grooves comprising an outer straight groove section, an oblique groove section and an inner straight groove section, the outer straight groove section and the oblique groove section being symmetrically arranged on both sides of the inner straight groove section, and the groove depth of the inner straight groove section being less than the groove depth of the outer straight groove section; a plurality of crescent grooves with equal spacing are provided on the large teeth of the rotor body, the crescent grooves corresponding to the outer straight groove section, the oblique groove section and the inner straight groove section respectively, and the depth of the crescent grooves corresponding to the oblique groove section gradually decreases from the outside to the inside, the depth of the crescent groove corresponding to the outer straight groove section is greater than the depth of the crescent groove corresponding to the oblique groove section, and the depth of the crescent groove corresponding to the oblique groove section is greater than the depth of the crescent groove corresponding to the inner straight groove section.

[0010] Preferably, the depth of each crescent groove on the large tooth corresponding to the outer straight groove section is equal, and the depth of each crescent groove corresponding to the inner straight groove section is equal.

[0011] Preferably, the crescent groove depth is calculated based on the wire embedding groove depth, and the crescent groove depth calculation formula is:

[0012] d=a×h

[0013] In the formula, d is the depth of the crescent groove, h is the depth of the wire groove, and a is the depth coefficient. The range of the crescent groove depth coefficient corresponding to the outer straight groove section is 1.03-1.1, the range of the crescent groove depth coefficient corresponding to the oblique groove section is 0.96-1.02, and the range of the crescent groove depth coefficient corresponding to the inner straight groove section is 0.85-0.95.

[0014] The present invention also provides another stiffness-compensated generator rotor, comprising a rotor body, wherein the rotor body is provided with a ventilation sub-groove with a variable cross-section, the ventilation sub-groove comprising a plurality of step groove segments, the groove depths of the plurality of step groove segments gradually decreasing from the outside to the inside along the axial direction of the rotor body, and the groove depths of the same step groove segment are equal; the large teeth of the rotor body are provided with a plurality of crescent grooves with equal spacing, the crescent grooves respectively corresponding to the plurality of step groove segments, and the depth of the crescent grooves corresponding to the outer step groove segments is greater than the depth of the crescent grooves corresponding to the inner step groove segments.

[0015] Preferably, the depths of the crescent grooves corresponding to the same stepped groove section on the large teeth are equal.

[0016] Preferably, the crescent groove depth is calculated based on the wire embedding groove depth, and the calculation formula for the crescent groove depth corresponding to the outermost stepped groove section is:

[0017] d=c×h

[0018] Wherein, d is the depth of the crescent groove corresponding to the outermost step groove section, h is the depth of the wire groove, and c is the crescent groove depth coefficient corresponding to the outermost step groove section, and the range of c is 0.8-1.

[0019] Preferably, the depth of the crescent groove corresponding to the inner step groove section on the large tooth is calculated based on a fixed decrement, with the depth of the crescent groove corresponding to the outermost step groove section as the starting point of the calculation. The depth of the crescent groove corresponding to the inner step groove section is equal to the depth of the crescent groove corresponding to the outer step groove section minus the fixed decrement.

[0020] Preferably, the fixed decrement is calculated based on the depth of the wire embedding groove, and the calculation formula of the fixed decrement is:

[0021] f=k×h

[0022] Where f is the fixed decrement, h is the depth of the wire groove, and k is the decrement coefficient, with the range of k being 0.01-0.05.

[0023] Preferably, the transverse width of the crescent groove is calculated according to the depth of the crescent groove, and the calculation formula of the transverse width of the crescent groove is:

[0024] L=n×d

[0025] Where L is the transverse width of the crescent groove, d is the depth of the crescent groove, and n is the width coefficient, with the range of n being 2.6-3.

[0026] Preferably, the spacing between the crescent grooves is calculated based on the depth of the wire embedding groove, and the calculation formula for the spacing between the crescent grooves is:

[0027] m=p×h

[0028] Where m is the distance between the crescent grooves, h is the depth of the wire groove, and p is the spacing coefficient. The range of p is 2.2-2.8.

[0029] Preferably, the bottom of the crescent groove is an arc-shaped structure.

[0030] The advantages of adopting the present invention are:

[0031] 1. The present invention provides a generator rotor with a stiffness compensation structure. First, by distributing multiple crescent grooves on the large teeth at equal intervals, the uniformity of the rotor structure is ensured, the dynamic balance performance of the rotor is optimized, and the processing consistency is improved.

[0032] Secondly, by arranging the crescent grooves to correspond to the outer straight groove section, the bevel groove section, and the inner straight groove section, and by gradually decreasing the depth of the crescent grooves corresponding to the bevel groove section from the outside to the inside, the crescent groove depth corresponding to the outer straight groove section is greater than the crescent groove depth corresponding to the bevel groove section, and the crescent groove depth corresponding to the bevel groove section is greater than the crescent groove depth corresponding to the inner straight groove section. This design ensures that the different depths of the crescent grooves correspond to different groove sections of the ventilation sub-groove. The design in which the depth of the crescent groove decreases as the groove depth of different groove sections in the variable-section ventilation sub-groove decreases effectively compensates for the effect of the cross-sectional difference caused by the change in the groove depth of the ventilation sub-groove on the structural stiffness of the large and small teeth, thereby achieving rotor stiffness compensation, effectively balancing the stiffness distribution of the large and small teeth, significantly reducing rotor vibration, and improving operational stability.

[0033] In addition, compared with the axial groove formed by the axial full-length milling technology, the crescent groove structure design adopted by the present invention has better control over the loss of the pole surface magnetic conductive area, effectively reducing the ineffective loss of the magnetic conductive material.

[0034] In summary, the present invention establishes a compensation mechanism for the relationship between the crescent groove depth and the different groove sections of the ventilation sub-groove, targeting the characteristics of different groove sections of the variable-section ventilation sub-groove: by making the crescent groove depth decrease as the ventilation sub-groove depth decreases, a differentiated stiffness compensation effect is formed on the large and small tooth structures of the rotor. This design breaks through the traditional idea of ​​uniform compensation, achieves precise control of the stiffness imbalance problem caused by changes in the cross-section of the ventilation sub-groove, and constructs a stiffness compensation system that dynamically matches the structural characteristics of the rotor. It effectively solves the technical problem of significant stiffness differences between large and small teeth at different cross-sectional positions of the rotor in the prior art, meets the actual demand for stiffness balance between large and small teeth, and improves the overall stability and reliability of the rotor operation.

[0035] 2. In the present invention, the stress distribution of the generator rotor is optimized by designing that the depth of each crescent groove corresponding to the outer straight groove section on the large tooth is equal, and the depth of each crescent groove corresponding to the inner straight groove section is equal.

[0036] 3. In the present invention, the proportional relationship between the crescent groove depth and the wire embedding groove depth is set differently, that is, the crescent groove depth is calculated based on the wire embedding groove depth, the crescent groove depth coefficient corresponding to the outer straight groove section is in the range of 1.03-1.1, the crescent groove depth coefficient corresponding to the oblique groove section is in the range of 0.96-1.02, and the crescent groove depth coefficient corresponding to the inner straight groove section is in the range of 0.85-0.95, thereby further reducing the stiffness difference between the large and small teeth.

[0037] Taking a 300 MW steam turbine generator rotor as an example, analytical calculations show that, using crescent slots of the same specifications and shape in the prior art, the stiffness difference between the large and small teeth of the crescent slots at different rotor cross-sectional positions is approximately 3%. In the present invention, the crescent slot depth corresponding to the outer straight slot section is selected to be 1.05 times the wire-embedded slot depth, and the crescent slot depth corresponding to the inner straight slot section is selected to be 0.95 times the wire-embedded slot depth. As a result, the stiffness difference between the large and small teeth of the crescent slots at different rotor cross-sectional positions is controlled within 0.2%.

[0038] 4. In the present invention, firstly, by adopting multiple stepped groove sections to form a variable-section ventilation sub-groove structure, the cooling medium forms a gradient pressure field inside the rotor, thereby improving the cooling efficiency; secondly, the different depths of the multiple crescent grooves on the large teeth correspond to the different stepped groove sections of the ventilation sub-groove, and the depth of the crescent groove decreases step by step with the decreasing groove depth of different groove sections in the variable-section ventilation sub-groove, effectively compensating for the influence of the cross-sectional difference caused by the change in groove depth on the structural stiffness of the large and small teeth, thereby realizing the stiffness compensation of the rotor.

[0039] 5. In the present invention, the proportional relationship between the crescent groove depth and the wire embedding groove depth is set differentially, that is, the crescent groove depth is calculated based on the wire embedding groove depth, and the range value of the crescent groove depth coefficient corresponding to the outermost step groove section is set to 0.8-1; and the crescent groove depth corresponding to the inner step groove section on the large tooth is calculated based on a fixed decrement, with the crescent groove depth corresponding to the outermost step groove section as the calculation starting point, and the crescent groove depth corresponding to the inner step groove section is equal to the crescent groove depth corresponding to the outer step groove section minus the fixed decrement; and the fixed decrement is calculated based on the wire embedding groove depth, and the decrement coefficient range value of the fixed decrement is set to 0.01-0.05, thereby further reducing the stiffness difference between the large and small teeth.

[0040] Taking a 300 MW steam turbine generator rotor as an example, analytical calculations show that using crescent grooves of the same specifications and shape in the prior art, the stiffness difference between the large and small teeth of the crescent grooves at different cross-sectional positions of the rotor is approximately 3%. In the present invention, the crescent groove depth of the outermost stepped groove section is selected to be 0.95 times the wire-embedded groove depth, and a fixed decrement of 0.025 is selected. As a result, the stiffness difference between the large and small teeth of the crescent grooves at different cross-sectional positions of the rotor is controlled within 0.3%.

[0041] 6. In the present invention, the arc-shaped structure design of the crescent groove bottom is compared with the crescent groove structure with a flat bottom and a straight groove bottom in the patent document with announcement number CN202309262U. This avoids the problem of local overheating caused by the traditional flat bottom and straight groove being too close to the wire embedding groove, thereby improving the reliability of the rotor operation.

[0042] 7. In the present invention, a design is adopted in which the lateral width of the crescent groove increases as the depth of the crescent groove itself increases. The correlation between the lateral width and the depth can be realized synchronously by simply adjusting the processing depth of the tool. This not only simplifies the tool path planning, but also ensures the consistency of the processing size, and significantly improves the processing efficiency and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the rotor structure in which the ventilation auxiliary slots are oblique auxiliary slots in the present invention;

[0044] Figure 2 This is a schematic structural diagram of the ventilation auxiliary groove in the present invention being an oblique auxiliary groove;

[0045] Figure 3 Schematic diagram of the structure of the crescent groove in the present invention;

[0046] Figure 4 Schematic diagram of the rotor structure in which the ventilation auxiliary grooves are stepped auxiliary grooves in the present invention;

[0047] Figure 5 This is a schematic structural diagram of the ventilation auxiliary groove in the present invention as a stepped auxiliary groove;

[0048] Figure 6 Schematic diagram of the rotor structure in the prior art;

[0049] Figure 7 This is a cross-sectional diagram of a large tooth with an axial groove in the prior art;

[0050] Figure 8 It is a schematic cross-sectional structural diagram of a rotor in the prior art;

[0051] Figure 9 It is a structural schematic diagram of a straight ventilation auxiliary groove in the prior art.

[0052] The numbers in the figure are: 1. rotor body, 2. small tooth, 3. large tooth, 4. axial groove, 5. ventilation auxiliary groove, 6. step auxiliary groove, 7. oblique auxiliary groove, 8. straight auxiliary groove, 9. embedded line groove, 10. crescent groove, 11. outer straight groove section, 12. oblique groove section, 13. inner straight groove section, 14. rotor center line, 15. boundary line. DETAILED DESCRIPTION

[0053] To further clarify the objectives, technical solutions, and advantages of the embodiments of the present invention, the following provides a clear and complete description of the technical solutions of the embodiments of the present invention, in conjunction with the accompanying drawings. For ease of description, the relative positions of the various components are described based on the layout of the accompanying drawings. For example, the positions of front, back, top, bottom, left, and right are determined based on the layout of the accompanying drawings.

[0054] Example 1

[0055] This embodiment provides a generator rotor with stiffness compensation, such as Figure 1-2 As shown, it includes a rotor body 1. The rotor body 1 is provided with a ventilation auxiliary slot 5 with a variable cross-section. The ventilation auxiliary slot 5 is arranged axially along the rotor body 1. The ventilation auxiliary slot 5 includes an outer straight slot segment 11, an oblique slot segment 12, and an inner straight slot segment 13. The outer straight slot segment 11 and the oblique slot segment 12 are symmetrically arranged on both sides of the inner straight slot segment 13. The inner straight slot segment 13 is symmetrically distributed in the middle area of ​​the rotor body 1 along the rotor centerline 14.

[0056] Furthermore, the groove depth of the inner straight groove section 13 is less than the groove depth of the outer straight groove section 11; the groove depth of the skew groove section 12 gradually decreases toward the rotor centerline 14. Figure 2It is understood that, generally, the depth h of the wire embedding groove 9 is approximately 0.3 times the radius R of the rotor body 1, i.e., h ≈ 0.3R. The intersection of the wire embedding groove 9 and the ventilation auxiliary groove 5 defines a boundary line 15. The groove bottom of the outer straight groove section 11 maintains a constant distance of approximately 0.5h from the boundary line 15; the groove bottom of the inner straight groove section 13 maintains a constant distance of approximately 0.1h from the boundary line 15; and the distance between the groove bottom of the skewed groove section 12 and the boundary line 15 exhibits a continuous linear decrease from the outside to the inside along the axis of the rotor body 1. That is, on the skewed groove section 12, the closer the groove bottom position is to the rotor centerline 14, the smaller the distance between the groove bottom position and the boundary line 15. Therefore, the ventilation auxiliary groove 5 exhibits the structural characteristics of the skewed auxiliary groove 7.

[0057] Continue to refer Figure 1 In this embodiment, a plurality of crescent grooves 10 with equal spacing are provided on the large teeth of the rotor body 1. The crescent grooves 10 correspond to the outer straight groove section 11, the oblique groove section 12, and the inner straight groove section 13, respectively. The depth of the crescent grooves 10 corresponding to the oblique groove section 12 gradually decreases from the outside to the inside. The depth of the crescent grooves 10 corresponding to the outer straight groove section 11 is greater than the depth of the crescent grooves 10 corresponding to the oblique groove section 12, and the depth of the crescent grooves 10 corresponding to the oblique groove section 12 is greater than the depth of the crescent grooves 10 corresponding to the inner straight groove section 13.

[0058] Therefore, in this embodiment, different depths of the crescent groove correspond to different slot sections of the ventilation sub-groove, and the depth of the crescent groove decreases as the slot depths of different slot sections in the variable-section ventilation sub-groove decrease, effectively compensating for the influence of the cross-sectional difference caused by the change in slot depth on the stiffness of the large and small teeth structures, thereby realizing stiffness compensation of the rotor.

[0059] Example 2

[0060] Based on Example 1, this example optimizes the depth of the crescent grooves 10. Specifically, the depth of each crescent groove 10 corresponding to the outer straight groove section 11 on the large tooth is equal, and the depth of each crescent groove 10 corresponding to the inner straight groove section 13 is equal.

[0061] Further, combined Figure 1 、 Figure 3 It is understood that the depth of the crescent groove 10 is calculated based on the depth of the wire groove 9. The calculation formula for the depth of the crescent groove 10 is:

[0062] d=a×h

[0063] In the formula, d is the depth of the crescent groove, h is the depth of the wire groove, and a is the depth coefficient. The range of the crescent groove depth coefficient corresponding to the outer straight groove section is 1.03-1.1, the range of the crescent groove depth coefficient corresponding to the oblique groove section is 0.96-1.02, and the range of the crescent groove depth coefficient corresponding to the inner straight groove section is 0.85-0.95.

[0064] like Figure 3As shown, the bottom of the crescent groove 10 is an arc-shaped structure. The transverse width of the crescent groove 10 is calculated based on the depth of the crescent groove 10, and the calculation formula is:

[0065] L=n×d

[0066] Where L is the transverse width of the crescent alveolar groove, d is the crescent alveolar depth, and n is the width coefficient, with n ranging from 2.6 to 3. It should be noted that the ratio of crescent alveolar groove depth to transverse width in this calculation formula is specific to a single crescent alveolar groove; that is, the transverse width of each crescent alveolar groove is determined solely by the depth and width coefficient corresponding to that crescent alveolar groove.

[0067] When processing the crescent groove 10: with point O as the center of the circle, fix the tool with a radius of R1, and change the size of the crescent groove by changing the distance between the tool and the large tooth. At this time, the lateral width L of the crescent groove 10 increases with the increase of the depth d of the crescent groove 10 itself.

[0068] In some embodiments, the transverse width L of the crescent groove 10 may also remain unchanged, which can be achieved by replacing a tool with a radius different from R1 to change the shape of the crescent groove.

[0069] Furthermore, the spacing between the crescent grooves 10 is calculated based on the depth of the wire embedding groove 9, and the spacing calculation formula is:

[0070] m=p×h

[0071] Where m is the distance between the crescent grooves, h is the depth of the wire groove, and p is the spacing coefficient. The range of p is 2.2-2.8.

[0072] In this embodiment, taking a 300 MW steam turbine generator rotor as an example, through analytical calculation, the depth d of the crescent groove 10 corresponding to the outer straight groove section 11 is selected as 1.05 times the depth h of the wire embedding groove 9, the depth of the crescent groove 10 corresponding to the inner straight groove section 13 is selected as 0.95 times the depth h of the wire embedding groove 9, and the value of the spacing coefficient p is selected as 2.5. It is found that the stiffness difference between the large and small crescent groove teeth at different cross-sectional positions of the rotor body 1 is controlled within 0.2%.

[0073] Example 3

[0074] This embodiment provides a generator rotor with stiffness compensation, such as Figure 4-5 As shown, it includes a rotor body 1. The rotor body 1 is provided with a ventilation auxiliary groove 5 of variable cross-section, which is arranged axially along the rotor body 1. The ventilation auxiliary groove 5 includes multiple stepped groove segments, with the rotor centerline 14 as the inner side and the end surface of the rotor body 1 as the outer side. The groove depth of the multiple stepped groove segments decreases step by step from the outside to the inside along the axial direction of the rotor body 1. The multiple stepped groove segments are symmetrically arranged around the rotor centerline 14.

[0075] Furthermore, the groove depths of the same step groove sections are equal. Figure 5 It is understood that, generally, the depth h of the wire embedding groove 9 is approximately 0.3 times the radius R of the rotor body 1, that is, h≈0.3R. The intersection of the wire embedding groove 9 and the ventilation auxiliary groove 5 defines the intersection line 15. The distance between the bottom of the outermost step groove section and the intersection line 15 is approximately 0.4h, and the distance between the bottom of the inner step groove section adjacent to the outermost step groove section and the intersection line 15 is approximately 0.3h. Continuing to adopt a stepped decreasing design, from the outermost step groove section inward, the distance between the bottom of each step groove section and the intersection line 15 decreases step by step. The specific decrease amount can be flexibly adjusted according to the ventilation efficiency requirements. As a result, the ventilation auxiliary groove 5 presents a structural step of the step auxiliary groove 6.

[0076] Continue to refer Figure 4 The large teeth of the rotor body 1 are provided with a plurality of crescent grooves 10 with equal spacing, and the crescent grooves 10 correspond to a plurality of stepped groove sections respectively, and the depth of the crescent grooves 10 corresponding to the outer stepped groove sections is greater than the depth of the crescent grooves 10 corresponding to the inner stepped groove sections.

[0077] Therefore, in this embodiment, different depths of the crescent groove correspond to different stepped groove sections of the ventilation sub-groove, and the depth of the crescent groove decreases step by step with the decreasing groove depth of different groove sections in the variable-section ventilation sub-groove, effectively compensating for the influence of the cross-sectional difference caused by the change in groove depth on the stiffness of the large and small teeth structure, thereby realizing the stiffness compensation of the rotor.

[0078] Example 4

[0079] Based on Example 3, this embodiment optimizes the depth of the crescent groove 10. Specifically, the crescent grooves 10 corresponding to the same stepped groove section on the large tooth have the same depth.

[0080] Combine Figure 4 It is understood that the depth of the crescent groove 10 is calculated based on the depth of the wire groove 9. The calculation formula for the depth of the crescent groove 10 corresponding to the outermost stepped groove section is:

[0081] d=c×h

[0082] Wherein, d is the depth of the crescent groove corresponding to the outermost step groove section, h is the depth of the wire groove, and c is the crescent groove depth coefficient corresponding to the outermost step groove section, and the range of c is 0.8-1.

[0083] Furthermore, the depth of the crescent groove 10 corresponding to the inner step groove section on the large tooth is calculated based on a fixed decrement, with the depth of the crescent groove 10 corresponding to the outermost step groove section as the starting point of the calculation. The depth of the crescent groove 10 corresponding to the inner step groove section is equal to the depth of the crescent groove corresponding to the outer step groove section minus the fixed decrement.

[0084] The fixed decrement is calculated based on the depth of the wire groove 9. The calculation formula for the fixed decrement is:

[0085] f=k×h

[0086] Where f is the fixed decrement, h is the depth of the wire groove, and k is the decrement coefficient, with the range of k being 0.01-0.05.

[0087] Furthermore, combined Figure 3 It is understood that the bottom of the crescent groove 10 is an arc-shaped structure. The transverse width of the crescent groove 10 is calculated based on the depth of the crescent groove 10, and the calculation formula is:

[0088] L=n×d

[0089] Where L is the transverse width of the crescent alveolar groove, d is the crescent alveolar depth, and n is the width coefficient, with n ranging from 2.6 to 3. It should be noted that the ratio of crescent alveolar groove depth to transverse width in this calculation formula is specific to a single crescent alveolar groove; that is, the transverse width of each crescent alveolar groove is determined solely by the depth and width coefficient corresponding to that crescent alveolar groove.

[0090] When processing the crescent groove 10: with point O as the center of the circle, fix the tool with a radius of R1, and change the size of the crescent groove by changing the distance between the tool and the large tooth. At this time, the lateral width L of the crescent groove 10 increases with the increase of the depth d of the crescent groove 10 itself.

[0091] In some embodiments, the transverse width L of the crescent groove 10 may also remain unchanged, which can be achieved by replacing a tool with a radius different from R1 to change the shape of the crescent groove.

[0092] Furthermore, the spacing between the crescent grooves 10 is calculated based on the depth of the wire embedding groove 9, and the spacing calculation formula is:

[0093] m=p×h

[0094] Where m is the distance between the crescent grooves, h is the depth of the wire groove, and p is the spacing coefficient. The range of p is 2.2-2.8.

[0095] In this embodiment, taking a 300 MW steam turbine generator rotor as an example, an analytical method is used to calculate the value of the crescent groove depth coefficient C corresponding to the outermost stepped groove section as 0.95, the value of k as 0.025, and the value of the spacing coefficient P as 2.5. It is found that the stiffness difference between the large and small teeth of the crescent groove at different cross-sectional positions of the rotor body 1 is controlled within 0.3%.

[0096] In summary, this invention addresses the characteristics of the different slot sections of the variable-section ventilation slots by establishing a compensation mechanism that correlates the crescent slot depth with the different slot sections. By decreasing the crescent slot depth as the ventilation slot depth decreases, a differentiated stiffness compensation effect is achieved on the rotor's large and small teeth. This design breaks through the traditional homogenization compensation approach, achieving precise control of the stiffness imbalance caused by variations in the ventilation slot cross section, and establishing a stiffness compensation system that dynamically matches the rotor's structural characteristics.

[0097] The above description is only a specific embodiment of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A stiffness-compensated generator rotor, comprising a rotor body (1), characterized in that: The rotor body (1) is provided with a ventilation auxiliary slot with a variable cross-section, the ventilation auxiliary slot comprising an outer straight slot section (11), an oblique slot section (12) and an inner straight slot section (13), the outer straight slot section (11) and the oblique slot section (12) being symmetrically arranged on both sides of the inner straight slot section (13), and the slot depth of the inner straight slot section (13) being smaller than the slot depth of the outer straight slot section (11); A plurality of crescent grooves (10) with equal spacing are provided on the large teeth of the rotor body (1), the crescent grooves (10) respectively corresponding to the outer straight groove section (11), the inclined groove section (12) and the inner straight groove section (13), and the depth of the crescent grooves (10) corresponding to the inclined groove section (12) gradually decreases from the outside to the inside, the depth of the crescent grooves (10) corresponding to the outer straight groove section (11) is greater than the depth of the crescent grooves (10) corresponding to the inclined groove section (12), and the depth of the crescent grooves (10) corresponding to the inclined groove section (12) is greater than the depth of the crescent grooves (10) corresponding to the inner straight groove section (13).

2. The generator rotor with stiffness compensation according to claim 1, characterized in that: The depth of each crescent groove (10) on the large tooth corresponding to the outer straight groove section (11) is equal, and the depth of each crescent groove (10) corresponding to the inner straight groove section (13) is equal.

3. The generator rotor with stiffness compensation according to claim 2, characterized in that: The depth of the crescent groove (10) is calculated based on the depth of the wire groove. The calculation formula for the depth of the crescent groove (10) is: d=a×h In the formula, d is the depth of the crescent groove, h is the depth of the wire groove, and a is the depth coefficient. The range of the crescent groove depth coefficient corresponding to the outer straight groove section is 1.03-1.1, the range of the crescent groove depth coefficient corresponding to the oblique groove section is 0.96-1.02, and the range of the crescent groove depth coefficient corresponding to the inner straight groove section is 0.85-0.

95.

4. The generator rotor with stiffness compensation according to claim 1, characterized in that: The transverse width of the crescent groove (10) is calculated based on the depth of the crescent groove (10). The calculation formula for the transverse width of the crescent groove (10) is: L=n×d Where L is the transverse width of the crescent groove, d is the depth of the crescent groove, and n is the width coefficient, with the range of n being 2.6-3.

5. The generator rotor with stiffness compensation according to claim 4, characterized in that: The spacing between the crescent grooves (10) is calculated based on the depth of the wire embedding groove, and the calculation formula for the spacing between the crescent grooves (10) is: m=p×h Where m is the distance between the crescent grooves, h is the depth of the wire groove, and p is the spacing coefficient. The range of p is 2.2-2.

8.

6. The generator rotor with stiffness compensation according to claim 5, characterized in that: The bottom of the crescent groove (10) is an arc-shaped structure.

7. A stiffness-compensated generator rotor, comprising a rotor body (1), characterized in that: The rotor body (1) is provided with a ventilation auxiliary groove with a variable cross-section, the ventilation auxiliary groove comprising a plurality of stepped groove sections, the groove depths of the plurality of stepped groove sections gradually decreasing from the outside to the inside along the axial direction of the rotor body (1), the plurality of stepped groove sections are symmetrically arranged with the rotor centerline (14) as the center, and the groove depths of the same stepped groove section are equal; A plurality of crescent grooves (10) with equal spacing are provided on the large teeth of the rotor body (1), the crescent grooves (10) respectively corresponding to a plurality of stepped groove sections, and the depth of the crescent grooves (10) corresponding to the outer stepped groove sections is greater than the depth of the crescent grooves (10) corresponding to the inner stepped groove sections.

8. The generator rotor with stiffness compensation according to claim 7, characterized in that: The crescent grooves (10) on the large teeth corresponding to the same stepped groove section have the same depth.

9. The generator rotor with stiffness compensation according to claim 8, characterized in that: The depth of the crescent groove (10) is calculated based on the depth of the wire embedding groove. The calculation formula for the depth of the crescent groove (10) corresponding to the outermost stepped groove section is: d=c×h Wherein, d is the depth of the crescent groove corresponding to the outermost step groove section, h is the depth of the wire groove, and c is the crescent groove depth coefficient corresponding to the outermost step groove section, and the range of c is 0.8-1.

10. The generator rotor with stiffness compensation according to claim 9, characterized in that: The depth of the crescent groove (10) corresponding to the inner step groove section on the large tooth is calculated according to a fixed decrement, with the depth of the crescent groove (10) corresponding to the outermost step groove section as the calculation starting point, and the depth of the crescent groove (10) corresponding to the inner step groove section is equal to the depth of the crescent groove corresponding to the outer step groove section minus the fixed decrement.

11. The generator rotor with stiffness compensation according to claim 10, characterized in that: The fixed decrement is calculated based on the depth of the wire groove. The calculation formula for the fixed decrement is: f=k×h Where f is the fixed decrement, h is the depth of the wire groove, and k is the decrement coefficient, with the range of k being 0.01-0.

05.

12. The generator rotor with stiffness compensation according to claim 7, characterized in that: The transverse width of the crescent groove (10) is calculated based on the depth of the crescent groove (10). The calculation formula for the transverse width of the crescent groove (10) is: L=n×d Where L is the transverse width of the crescent groove, d is the depth of the crescent groove, and n is the width coefficient, with the range of n being 2.6-3.

13. The generator rotor with stiffness compensation according to claim 12, characterized in that: The spacing between the crescent grooves (10) is calculated based on the depth of the wire embedding groove, and the calculation formula for the spacing between the crescent grooves (10) is: m=p×h Where m is the distance between the crescent grooves, h is the depth of the wire groove, and p is the spacing coefficient. The range of p is 2.2-2.

8.

14. The generator rotor with stiffness compensation according to claim 13, characterized in that: The bottom of the crescent groove (10) is an arc-shaped structure.

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