A slot wedge, a rotating shaft and a generator capable of reducing stress of a ventilation slot of a tooth portion of the rotating shaft

Abstract

The utility model relates to steam turbine generator structure design technical field, especially, a kind of slot wedge, shaft and generator capable of reducing the stress of shaft tooth part ventilation groove are provided, shoulder part is equipped on the slot wedge, contact surface for being used to contact with tooth part is equipped on the shoulder part;The through groove is also respectively equipped in the both sides of the slot wedge, the height direction and width direction of the through groove are penetrated shoulder part;The end of the shaft tooth part ventilation groove is located in the length range of the through groove.By slot wedge, shaft and generator, centrifugal force can be dispersed to the both sides of tooth part ventilation groove end, reduce tooth part ventilation groove end stress.

Description

Technical Field

[0001] This utility model relates to the field of steam turbine generator structural design technology, and in particular to a slot wedge, a shaft, and a generator that can reduce the stress of the ventilation slot in the shaft teeth. Background Technology

[0002] As a key component of a steam turbine generator set, the shaft directly determines the safe operation and service life of the unit. During operation, the coil bars generate a significant amount of heat, necessitating the design of ventilation slots in the shaft teeth. Simultaneously, the centrifugal force generated by the coil bars is transmitted to the shaft teeth via the slot wedges, causing stress concentration at the ends of the ventilation slots during shaft operation. The locations are shown in the attached instruction manual. Figure 8 As shown.

[0003] Currently, based on the structure of the shaft and slot wedge in traditional units, the centrifugal force F0 generated by the internal components of the shaft tooth groove during rotation is decomposed into F1 and F2 through the contact surface on the shoulder that transmits centrifugal force, and then acts on the shaft teeth, as shown in the instruction manual. Figure 7 As shown. This structure causes the ventilation slots to deform inwards on both sides during unit operation, resulting in higher stress at the end of the ventilation slots on the shaft teeth, as indicated in the instruction manual. Figure 9 As shown, the traditional slotted wedge structure poses a serious safety hazard to the long-term operation of the unit. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this utility model proposes a slot wedge, a rotating shaft, and a generator that can reduce the stress of the ventilation groove in the tooth section of the rotating shaft. It can disperse the centrifugal force to both sides of the end of the ventilation groove in the tooth section, thereby reducing the stress at the end of the ventilation groove in the tooth section.

[0005] This utility model is achieved by adopting the following technical solution: A slot wedge that can reduce the stress of the ventilation groove of the shaft tooth is provided. The slot wedge has a shoulder and a contact surface for contacting the tooth. A through groove is provided on both sides of the slot wedge, and the through groove extends through the height and width directions of the shoulder. The end of the ventilation groove of the shaft tooth is located within the length range of the through groove.

[0006] The groove wedge is a single-piece structure.

[0007] The groove wedge has a segmented structure, including a first groove wedge and a second groove wedge, with the first groove wedge located near the end of the rotating shaft.

[0008] The end faces of the first and second slot wedges are flush with each other and are also flush with the end of the ventilation groove of the shaft teeth.

[0009] The length of the through groove on the first grooved wedge is greater than the length of the through groove on the second grooved wedge.

[0010] The end faces of the first and second slotted wedges are offset from each other, and the end faces of the first and second slotted wedges cooperate with each other. The through groove is provided on the first or second slotted wedge.

[0011] A shaft that can reduce the stress of the ventilation groove in the shaft teeth includes shaft teeth, on which ventilation grooves are provided, and the aforementioned groove wedges are also provided between the shaft teeth.

[0012] A generator capable of reducing stress in the ventilation slots of the shaft teeth includes the aforementioned slot wedge.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. In this utility model, by setting through slots on both sides of the slot wedge, the end of the ventilation groove of the rotating shaft tooth is located within the length range of the through slot. The through slot extends through the height and width directions of the shoulder. By changing the contact surface, a stress buffer zone is established, making the through slot area a buffer zone for transmitting centrifugal force. This disperses the centrifugal force to both sides of the end of the tooth ventilation groove, significantly reducing stress concentration at the end of the tooth ventilation groove. Specifically, through the structure of this slot wedge, the stress at the end of the tooth ventilation groove can be reduced by approximately 60%.

[0014] 2. The groove wedge in this utility model is easy to process and can be executed.

[0015] 3. In this utility model, the groove wedge is a one-piece structure, which makes processing more convenient and the middle of the stress buffer zone is complete.

[0016] 4. When the end faces of the first and second slotted wedges are flush, and the length of the through groove on the first slotted wedge is greater than the length of the through groove on the second slotted wedge, it helps to maintain the uniformity of the structure and makes the overall slotted wedge structure more stable.

[0017] 5. The end faces of the first and second groove wedges are staggered, which can more effectively disperse centrifugal force and make the structure more stable. Attached Figure Description

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments, wherein: Figure 1 This is a schematic diagram of the groove wedge structure of this utility model. Figure 1 ; Figure 2 for Figure 1 A schematic diagram showing the relationship between the slot wedge and the rotating shaft; Figure 3 This is a schematic diagram of the groove wedge structure of this utility model. Figure 2 ; Figure 4 for Figure 3 A schematic diagram showing the relationship between the slot wedge and the rotating shaft; Figure 5 This is a schematic diagram of the groove wedge structure of this utility model. Figure 3 ; Figure 6 for Figure 5 A schematic diagram showing the relationship between the slot wedge and the rotating shaft; Figure 7 This is a schematic diagram of the existing slotted wedge structure and centrifugal force transmission. Figure 8 This is a schematic diagram of the existing slotted wedge structure and rotating shaft; Figure 9 A schematic diagram of the stress in the tooth ventilation groove under rated operating conditions, using the existing slot wedge structure; Marked in the image: 1. Groove wedge, 2. Shoulder, 3. Contact surface, 4. Through groove, 5. First groove wedge, 6. Second groove wedge. Detailed Implementation

[0019] Example 1 As a basic embodiment of this utility model, the utility model includes a slot wedge 1 for reducing the stress of the ventilation groove of the turbine generator shaft teeth. The slot wedge 1 is provided with a shoulder 2, and the shoulder 2 is provided with a contact surface 3 for contacting the teeth. A through groove 4 is also provided on both sides of the slot wedge 1, and the through groove 4 penetrates through the height and width directions of the shoulder 2. The end of the ventilation groove of the shaft teeth is located within the length range of the through groove 4.

[0020] Example 2 In a preferred embodiment of this utility model, the utility model includes a slot wedge 1 for reducing stress in the ventilation groove of the turbine generator shaft teeth. The slot wedge 1 has a shoulder 2, and the shoulder 2 has an inclined contact surface 3 for contacting the teeth. (See attached specification) Figure 1 The slotted wedge 1 is a single-section structure, and through slots 4 are respectively provided on both sides of the slotted wedge 1. The through slots 4 penetrate through the height and width directions of the shoulder 2, and the length of the through slots 4 is L4. Refer to the appendix of the specification. Figure 2 The end of the ventilation groove in the shaft tooth section is located within the length of the through groove 4. With this structure, a stress buffer zone of length L4 exists at the end of the ventilation groove in the shaft tooth section, and this stress buffer zone is intact in the middle. The size of L4 can be determined according to factors such as the unit speed.

[0021] Taking a domestic MW steam turbine generator as an example, the structure of slot wedge 1 described above is adopted, and the reasonable length of L4 is determined based on the unit speed, etc. The von Mies stress at the end of the ventilation slot of the shaft teeth is calculated using finite element software before and after slot wedge 1 optimization under rated and overspeed conditions. Stress evaluation is performed on the ends of the ventilation slots of three consecutive teeth in the middle of the shaft, and the optimization results are shown in Table 1.

[0022] Table 1. Stress evaluation at the end of the ventilation groove of the shaft tooth before and after slot wedge optimization.

[0023] Using the same unit, the length of L4 in slot wedge 1 was reduced by 5mm. The von Mies stress at the end of the ventilation slot of the shaft teeth was calculated using finite element software before and after slot wedge 1 optimization, under rated and overspeed conditions. Stress evaluation was performed on the ends of the ventilation slots of three consecutive teeth in the middle of the shaft, and the optimization results are shown in Table 2.

[0024] Table 2. Stress at the end of the ventilation groove in the shaft tooth before and after slot wedge optimization.

[0025] Example 3 In another preferred embodiment of this utility model, the utility model includes a slot wedge 1 for reducing stress in the ventilation groove of the turbine generator shaft teeth. The slot wedge 1 has a shoulder 2, and the shoulder 2 has a contact surface 3 for contacting the teeth. The slot wedge 1 has a segmented structure, specifically including a first slot wedge 5 and a second slot wedge 6, with the first slot wedge 5 located near the end of the shaft. (See attached specification) Figure 3 The end faces of the first slotted wedge 5 and the second slotted wedge 6 are flush, and each of the two adjacent ends of the first slotted wedge 5 and the second slotted wedge 6 is provided with a through groove 4, which penetrates the height and width directions of the shoulder 2. The length L1 of the through groove 4 on the first slotted wedge 5 is greater than the length L2 of the through groove 4 on the second slotted wedge 6. (Refer to the appendix of the specification.) Figure 4 The end faces of the first slot wedge 5 and the second slot wedge 6 are flush with the end of the ventilation groove of the shaft tooth, and the end of the ventilation groove of the shaft tooth is located within the length range of the through groove 4. Finally, stress buffers of lengths L1 and L2 are left at the ends of the first slot wedge 5 and the second slot wedge 6, respectively. The dimensions of L1 and L2 are determined according to factors such as the unit speed.

[0026] Taking a domestic MW steam turbine generator as an example, the aforementioned slot wedge 1 is used, and the reasonable lengths of L1 and L2 are determined based on the unit speed, etc. The von Mies stress at the end of the ventilation slot of the shaft teeth is calculated using finite element software before and after slot wedge 1 optimization under rated and overspeed conditions. Stress evaluation is performed on the ends of the ventilation slots of three consecutive teeth in the middle of the shaft, and the optimization results are shown in Table 3.

[0027] Table 3. Stress evaluation at the end of the ventilation groove of the shaft tooth before and after slot wedge optimization.

[0028] Example 4 In another preferred embodiment of this utility model, the utility model includes a slot wedge 1 for reducing stress in the ventilation groove of the turbine generator shaft teeth. The slot wedge 1 has a shoulder 2, and the shoulder 2 has a contact surface 3 for contacting the teeth. The slot wedge 1 has a segmented structure, specifically including a first slot wedge 5 and a second slot wedge 6, with the first slot wedge 5 located near the end of the shaft. The end faces of the first slot wedge 5 and the second slot wedge 6 are offset and cooperate with each other. Through grooves 4 are also provided on both sides of the first slot wedge 5 or the second slot wedge 6. In this embodiment, refer to the appendix of the specification. Figure 5 Preferably, the through groove 4 is disposed on the second groove wedge 6. The through groove 4 extends through the shoulder 2 of the second groove wedge 6 in both the height and width directions, and the length of the through groove 4 is L3. (Refer to the appendix of the specification.) Figure 6 The end of the ventilation groove in the shaft tooth section is located within the length of the through groove 4. This structural design creates a stress buffer zone with a distance of L3 at the end of the ventilation groove in the shaft tooth section; this stress buffer zone has a double-layer structure. The dimension of L3 can be determined based on factors such as the unit's rotational speed.

[0029] Taking a domestic MW steam turbine generator as an example, the structure of slot wedge 1 described above is adopted, and the reasonable length of L3 is determined based on the unit speed, etc. The von Mies stress at the end of the ventilation slot of the shaft teeth is calculated using finite element software before and after slot wedge 1 optimization under rated and overspeed conditions. Stress evaluation is performed on the ends of the ventilation slots of three consecutive teeth in the middle of the shaft, and the optimization results are shown in Table 4.

[0030] Table 4. Stress evaluation at the end of the ventilation groove of the shaft tooth before and after slot wedge optimization.

[0031] By combining the specific examples in Examples 2 to 4, the following conclusions can be drawn: 1. The structure of the slot wedge 1 in this application effectively reduces stress concentration at the end of the ventilation slot, with a reduction effect of approximately 60%; 2. The smaller the stress at the end of the ventilation groove under the original slot wedge, the more obvious the stress reduction effect of the structural optimization scheme. 3. The length of the stress buffer zone of the slot wedge 1 has a significant impact on the stress reduction effect at the end of the ventilation slot.

[0032] Example 5 In another preferred embodiment of this utility model, the utility model includes a rotating shaft that can reduce the stress of the ventilation groove in the rotating shaft teeth, including rotating shaft teeth, on which ventilation grooves are provided. A slot wedge 1 as described in any one of embodiments 1 to 4 is also provided between the rotating shaft teeth.

[0033] Example 6 As another preferred embodiment of the present invention, the present invention includes a generator that can reduce the stress of the ventilation groove of the shaft teeth, including the groove wedge 1 described in any one of the embodiments 1 to 4, or including the shaft in embodiment 5.

[0034] In summary, any other corresponding modifications made by those skilled in the art based on the technical solution and concept of this utility model without creative mental effort after reading this utility model document are all within the scope of protection of this utility model.

Claims

1. A slot wedge capable of reducing stress in the ventilation groove of a rotating shaft tooth, the slot wedge (1) having a shoulder (2), the shoulder (2) having a contact surface (3) for contacting the tooth; characterized in that: The groove wedge (1) is also provided with through grooves (4) on both sides, and the through grooves (4) penetrate the height and width directions of the shoulder (2); the end of the ventilation groove of the rotating shaft tooth is located within the length range of the through groove (4).

2. The slot wedge according to claim 1, which can reduce the stress of the ventilation groove in the shaft tooth, is characterized in that: The groove wedge (1) is a single-piece structure.

3. A slot wedge for reducing stress in the ventilation groove of a rotating shaft tooth according to claim 1, characterized in that: The slot wedge (1) is a segmented structure, including a first slot wedge (5) and a second slot wedge (6), with the first slot wedge (5) located near the end of the rotating shaft.

4. A slot wedge for reducing stress in the ventilation groove of a rotating shaft tooth according to claim 3, characterized in that: The end faces of the first groove wedge (5) and the second groove wedge (6) are flush with each other and are flush with the end of the ventilation groove of the shaft tooth.

5. A slot wedge for reducing stress in the ventilation groove of a rotating shaft tooth according to claim 4, characterized in that: The length of the through groove (4) on the first groove wedge (5) is greater than the length of the through groove (4) on the second groove wedge (6).

6. A slot wedge for reducing stress in the ventilation groove of a rotating shaft tooth according to claim 3, characterized in that: The end faces of the first groove wedge (5) and the second groove wedge (6) are respectively offset, and the end faces of the first groove wedge (5) and the second groove wedge (6) cooperate with each other. The through groove (4) is provided on the first groove wedge (5) or the second groove wedge (6).

7. A rotating shaft capable of reducing stress in the ventilation groove of the rotating shaft teeth, comprising rotating shaft teeth, wherein the rotating shaft teeth are provided with ventilation grooves, characterized in that: The toothed part of the shaft is further provided with a groove wedge (1) as described in any one of claims 1 to 6.

8. A generator capable of reducing stress in the ventilation grooves of the shaft teeth, characterized in that: Includes the slotted wedge (1) as described in any one of claims 1 to 6.

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