An embedded structure for a starter motor automatic seal stationary ring assembly
By incorporating a metal ring and wave spring limiting tongue structure into the starter motor's dynamic seal stationary ring assembly, combined with the annular groove on the inner circumferential surface of the graphite ring and the O-ring seal, the problems of multiple leakage channels, stress concentration, and easy breakage of the graphite ring in existing embedded structures are solved, achieving a long-life zero-leakage seal under high temperature and high speed.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU CAIC ELECTRONICS CO LTD
- Filing Date
- 2025-08-14
- Publication Date
- 2026-06-30
AI Technical Summary
The existing embedded structure of the starter motor automatic seal stationary ring assembly has problems such as multiple leakage channels, stress concentration and deformation leading to reduced sealing effect and reliability, low space utilization, and easy breakage of graphite ring.
A metal ring is set on the outer circumference and one axial side of the graphite ring. The wave spring and limiting tongue design, combined with the annular groove and O-ring on the inner circumference of the graphite ring, form a thin-walled circular ring structure, which provides clamping force and evenly distributes elastic force, eliminates leakage channels, and enhances the strength and anti-rotation function of the graphite ring.
It significantly improves the structural strength and crack resistance of graphite rings in confined spaces, reduces leakage channels, reduces stress concentration, improves sealing reliability and service life, and can work stably at high temperature and high speed.
Smart Images
Figure CN224433410U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of starter motor sealing components, specifically relating to an embedded structure of a starter motor sealing stationary ring component. Background Technology
[0002] In high-speed rotating machinery such as aircraft turbine starters, the performance of dynamic sealing components is crucial to the safe operation and efficiency of the equipment, especially the rotary seal at the turbine end, which must effectively prevent leakage of media such as lubricating oil during high-speed rotation. Starter dynamic sealing components typically consist of a dynamic ring, a stationary ring assembly, and O-rings, assembled inside the turbine assembly, and perform a critical sealing function.
[0003] However, the high-speed operation of the turbine starter (reaching tens of thousands of revolutions per minute) generates a large amount of frictional heat at the sealing contact surface. Simultaneously, limited installation space (the axial working height is typically only about 10mm) and a limited volume of lubricating oil with virtually no circulation result in significant heat accumulation and a substantial temperature rise. Therefore, the sealing components must be capable of stable operation in high-temperature environments (typically requiring tolerance above 150°C).
[0004] The graphite ring in the stationary ring assembly is a brittle material, prone to fracture under high temperature or mechanical stress. To prevent serious consequences from graphite ring fracture (such as debris entering the starter turbine and causing an accident), traditional designs use an inlay structure where a metal ring clamps the graphite ring. This traditional inlay structure surrounds the outer diameter of the graphite ring, the wave spring side, and the area below the inner diameter, creating multiple potential leakage paths, including the leakage paths between the contact face of the moving ring and the graphite ring, the contact face between the rubber seal and the metal ring, and the contact face between the graphite ring and the metal ring seat. To prevent leakage between the graphite ring and the metal ring seat, a large interference fit is required for inlay, and adhesive must be used for bonding. However, this method leads to large contact stress and residual stress on the graphite ring, which may cause plastic deformation, cracks, or even end face deformation of the graphite, seriously affecting the sealing effect and reducing the reliability of the dynamic sealing assembly. In addition, in the traditional structure, the metal ring seat surrounds the graphite ring in three directions, occupying a large space and making the graphite ring appear thinner in the radial direction, increasing the risk of fracture. Utility Model Content
[0005] To address the aforementioned shortcomings of existing technologies, this utility model provides an embedded structure for a starter motor automatic seal stationary ring assembly, which solves the problems of multiple leakage channels, stress concentration and deformation leading to reduced sealing effect and reliability, and low space utilization causing the graphite ring to be easily broken in existing starter motor automatic seal stationary ring assembly embedded structures.
[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0007] An embedded structure for a starter motor automatic sealing stationary ring assembly is provided, including a graphite ring and a metal ring. The metal ring is disposed on the outer circumferential surface and one axial end side of the graphite ring. A wave spring is disposed on the metal ring, and a limiting tongue is disposed on the wave spring. The limiting tongue is evenly disposed along the circumferential direction of the wave spring. An annular groove is disposed on the inner circumferential surface of the graphite ring, and a sealing ring is disposed in the annular groove.
[0008] The beneficial effects of the above technical solution are as follows: the metal ring is set on the outer circumference of the graphite ring and on the side facing the wave spring, and the graphite ring does not extend below the inner diameter of the graphite ring, forming a thin-walled circular ring structure, which can provide clamping force and prevent the graphite ring from breaking as a whole; the wave spring is directly set on the end face of the metal ring, so that the force is not applied to the back of the graphite ring, but the elastic force of the wave spring is evenly distributed on the metal ring, and then transmitted to the graphite ring through the metal ring, avoiding plastic deformation or cracks in the graphite ring caused by uneven local force. At the same time, the continuous elastic force provided by the wave spring ensures a tight fit between the moving ring and the end face of the graphite ring, thereby forming an effective seal of the first leakage channel; a limit tongue is provided on the side of the metal ring near the wave spring. Furthermore, the limiting tongue is evenly distributed around the circumference of the wave spring, which not only limits the axial compression of the wave spring but also prevents the wave spring from being compressed and causing plastic deformation and elasticity loss. At the same time, it prevents the tail of the graphite ring from being damaged by excessive compression of the spring, thus maintaining a long-term stable sealing force and reliability. An O-ring is installed in the annular groove on the inner circumference of the graphite ring, which can form a radial sealing interface with the starter housing, constituting the sealing point of the second leakage channel. Since the sealing ring is directly compressed by the graphite ring body and does not pass through the metal ring, there is no leakage gap between the metal ring and the graphite ring, which effectively reduces the number of leakage channels, reduces the interference fit, and reduces the stress and deformation of the graphite ring.
[0009] This inlay structure, by placing the metal ring only on the outer circumference of the graphite ring and on the side facing the wave spring, allows the graphite ring to achieve 30%–50% axial thickening and 80%–100% radial thickening within a space of only 10mm in axial length. This significantly improves the structural strength of the graphite ring and avoids the radial thin-wall phenomenon caused by the metal ring encircling the ring on three sides in existing structures. This reduces the risk of the graphite ring cracking due to stress concentration when the starter rotates at high speed.
[0010] Furthermore, the outer circumferential surface of the metal ring is provided with anti-rotation bosses.
[0011] The beneficial effects of adopting the above technical solution are as follows: the anti-rotation boss is integrally formed with the outer circumferential surface of the metal ring. When the rotating ring rotates at high speed, the anti-rotation boss and the starter housing form a rigid circumferential limit, ensuring that the entire stationary ring assembly will not rotate. This avoids circumferential slippage between the graphite ring and the rotating ring, which not only maintains the stable fit of the end face seal, but also prevents additional frictional heat and wear caused by relative rotation, fundamentally improving the sealing reliability and service life.
[0012] Furthermore, the axial height of the limiting tongue is less than the free height of the wave spring, and the axial height of the limiting tongue is greater than the compressive height of the wave spring.
[0013] The beneficial effects of adopting the above technical solution are as follows: when the axial height of the tongue is less than the free height of the wave spring, but greater than the compressive height of the wave spring, it can avoid uneven force on the graphite ring caused by radial offset of the wave spring, and it will not be compressed to the compressive height, resulting in plastic deformation or force loss. Thus, it can maintain a continuous and constant elastic force output, ensuring that the dynamic ring and the end face of the graphite ring are always tightly fitted, while preventing the tail of the graphite ring from cracking due to excessive pressure, significantly improving sealing reliability and component life.
[0014] Furthermore, the height of the limiting tongue is greater than the height of the graphite ring tail.
[0015] The beneficial effects of adopting the above technical solution are as follows: When the axial height of the limiting tongue is greater than the height of the graphite ring tail, the limiting tongue can contact the graphite ring tail first when the wave spring is compressed, and the graphite ring tail can contact the graphite ring tail later. Therefore, the limiting tongue forms a block, which can prevent the graphite ring tail from being further squeezed and deformed or cracked by the wave spring, thus avoiding cracks caused by local overload of brittle graphite. At the same time, it can limit the maximum compression stroke of the wave spring, preventing the wave spring from being compressed and causing plastic deformation or elasticity attenuation, ensuring a tight fit between the moving ring and the graphite ring end face, thereby improving the sealing reliability and durability.
[0016] Furthermore, there are four limiting tongues.
[0017] The beneficial effects of adopting the above technical solution are as follows: by setting four limiting tongues, the wave spring can be evenly supported at four points in the circumferential direction, which not only avoids the skewing or twisting of the wave spring caused by uneven force, but also evenly transmits the elastic force to the end faces of the metal ring and the graphite ring, thereby ensuring that the fit between the moving ring and the graphite ring is always consistent. At the same time, the symmetrical arrangement of the four points reduces the stress of single-point contact and prevents uneven force on the tail of the graphite ring, thereby further reducing the risk of cracking and improving the sealing life.
[0018] Furthermore, there is an interference fit between the metal ring and the graphite ring.
[0019] The beneficial effects of adopting the above technical solution are as follows: a very small interference fit can be achieved between the metal ring and the graphite ring, which can provide clamping force to prevent the graphite ring from breaking as a whole, and avoid the high contact stress and residual stress caused by the large interference fit required by the three-sided encirclement in the existing structure. This significantly reduces the risk of plastic deformation and cracking of the graphite ring. At the same time, it can achieve the anti-rotation function of the metal ring on the graphite ring, and reduce the metal part extending below the inner diameter of the graphite ring, thus eliminating the third leakage channel in the existing structure, thereby further improving the sealing reliability and durability.
[0020] In summary, the embedded structure of the starter motor automatic sealing stationary ring assembly provided by this utility model has the following advantages:
[0021] This inlay structure, by placing a metal ring on the outer circumference of the graphite ring and on the side facing the wave spring, eliminates the metal surround extending below the inner diameter of the graphite ring in existing inlay structures. This allows for an axial thickening of the graphite ring of 30%–50% and a radial thickening of 80%–100% within a 10mm axial length that remains unchanged, significantly improving the strength and crack resistance of the brittle graphite ring. Furthermore, the metal ring and graphite ring employ a small interference fit, which both tightens the graphite ring to prevent overall breakage and, through the integrated anti-rotation boss on the outer circumference of the metal ring, rigidly engages with the starter housing to prevent the stationary ring from rotating, eliminating the risks of high contact stress, residual stress, and high-temperature adhesive failure associated with traditional large interference fits. Additionally, four limiting tongues are evenly distributed on the metal ring, with the axial... The height is between the free height and the high-pressure height of the wave spring, which prevents the spring from being compressed and causing plastic deformation and force loss, and also avoids excessive compression of the graphite ring tail. At the same time, the inner diameter of the graphite ring is provided with an annular groove, and an O-ring is provided in the annular groove to form a radial seal with the starter housing, replacing the traditional metal ring transition seal. This reduces the leakage channels from three to two, completely eliminating the third leakage channel between the graphite ring and the metal ring, significantly reducing stress concentration and end face deformation, and improving sealing reliability. In addition, there is no adhesive layer between the inner circumference of the metal ring and the outer circumference of the graphite ring, which can withstand high temperatures above 300°C under glue-free conditions, achieving a long-life, zero-leakage dynamic seal under high speed and high temperature conditions in a confined space. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the structure of this utility model;
[0023] Figure 2 This is a schematic diagram of the structure of the metal ring and the wave spring in this utility model;
[0024] Figure 3 This is a schematic diagram of the assembly of the metal ring and the graphite ring in this utility model;
[0025] Among them, 1. Metal ring; 2. Graphite ring; 3. Moving ring; 4. Wave spring; 5. First leakage channel; 6. Second leakage channel; 7. Limiting tongue; 8. Anti-rotation boss; 9. Sealing ring. Detailed Implementation
[0026] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of this utility model as defined and determined by the appended claims, these changes are obvious. All utility model creations utilizing the concept of this utility model are within the scope of protection.
[0027] like Figures 1-3As shown, the embedded structure of the starter motor sealing stationary ring assembly provided by this utility model includes a graphite ring 2 and a metal ring 1. The metal ring 1 is disposed on the outer circumferential surface and one axial end side of the graphite ring 2, and the metal ring 1 and the graphite ring 2 are interference-fitted. A wave spring 4 is disposed on the metal ring 1, and a limiting tongue 7 is disposed on the wave spring 4. The limiting tongue 7 is evenly disposed along the circumferential direction of the wave spring 4. An annular groove is disposed on the inner circumferential surface of the graphite ring 2, and a sealing ring 9 is disposed in the annular groove. The axial thickness of the graphite ring 2 is 1.3 to 1.5 times that of the existing structure, and the radial thickness is 1.8 to 2 times that of the existing structure. This inlay structure, by placing the metal ring 1 only on the outer circumference of the graphite ring 2 and on the side facing the wave spring 4, allows the graphite ring 2 to achieve an axial thickening of 30% to 50% and a radial thickening of 80% to 100% within a space of only 10mm in axial length. This significantly improves the structural strength of the graphite ring 2 and avoids the radial thin-wall phenomenon caused by the metal ring 1 encircling the ring on three sides in the existing structure. This reduces the risk of the graphite ring 2 cracking due to stress concentration when the starter rotates at high speed. The metal ring 1 is located on the outer circumference of the graphite ring 2 and on the side facing the wave spring 4. The graphite ring 2 does not extend below its inner diameter, forming a thin-walled circular structure that provides clamping force and prevents the graphite ring 2 from breaking completely. The wave spring 4 is directly located on the end face of the metal ring 1, preventing the force from being applied to the back of the graphite ring 2. This allows the elastic force of the wave spring 4 to be evenly distributed on the metal ring 1, and then transmitted to the graphite ring 2. This avoids plastic deformation or cracks in the graphite ring 2 caused by uneven local stress. Simultaneously, the continuous elastic force provided by the wave spring 4 ensures a tight fit between the moving ring 3 and the end face of the graphite ring 2, thus forming an effective seal for the first leakage channel 5. A limiting tongue 7 is provided on the side of the metal ring 1 near the wave spring 4. The limiting tongue 7 is evenly arranged along the circumference of the wave spring 4, which not only limits the axial compression of the wave spring 4, but also prevents the wave spring 4 from being compressed and causing plastic deformation and loss of elasticity. At the same time, it prevents the tail of the graphite ring 2 from being squeezed and damaged due to excessive compression of the spring, thus maintaining a long-term stable sealing force value and reliability. An O-ring seal 9 is set in the annular groove on the inner circumference of the graphite ring 2, which can form a radial sealing interface with the starter housing, constituting the sealing point of the second leakage channel 6. Since the sealing ring 9 is directly compressed by the graphite ring 2 body and does not pass through the metal ring 1, there is no leakage gap between the metal ring 1 and the graphite ring 2, which effectively reduces the number of leakage channels, reduces the interference, and reduces the stress and deformation of the graphite ring 2.
[0028] like Figure 2As shown, an anti-rotation boss 8 is provided on the outer circumferential surface of the metal ring 1. The anti-rotation boss 8 is integrally formed with the outer circumferential surface of the metal ring 1. When the rotating ring 3 rotates at high speed, the anti-rotation boss 8 forms a rigid circumferential limit with the starter housing, ensuring that the entire stationary ring assembly will not rotate. This avoids circumferential slippage between the graphite ring 2 and the rotating ring 3, maintaining a stable fit of the end face seal and preventing additional frictional heat and wear caused by relative rotation, fundamentally improving the sealing reliability and service life.
[0029] like Figure 2 As shown, four limiting tongues 7 are provided, and the axial height of the limiting tongues 7 is less than the free height of the wave spring 4, while the axial height of the limiting tongues 7 is greater than the forced pressure height of the wave spring 4. When the axial height of the limiting tongues is less than the free height of the wave spring 4, but greater than the forced pressure height of the wave spring 4, uneven force on the graphite ring caused by radial offset of the wave spring can be avoided, and it will not be compressed to the forced pressure height, resulting in plastic deformation or force loss. This maintains a continuous and constant elastic force output, ensuring that the moving ring 3 and the end face of the graphite ring 2 are always tightly fitted, while preventing the tail of the graphite ring 2 from cracking due to excessive pressure, significantly improving sealing reliability and component life.
[0030] like Figure 2 As shown, the height of the limiting tongue 7 is greater than the height of the tail of the graphite ring 2. When the axial height of the limiting tongue 7 is greater than the height of the tail of the graphite ring 2, the limiting tongue 7 will contact the tail of the graphite ring 2 first when the wave spring 4 is compressed. Therefore, the limiting tongue 7 forms a barrier, preventing the tail of the graphite ring 2 from being further squeezed, deformed, or cracked by the wave spring 4. This avoids cracks caused by local overload in brittle graphite. At the same time, it limits the maximum compression stroke of the wave spring 4, preventing the wave spring 4 from being compressed and causing plastic deformation or elasticity attenuation. This ensures a tight fit between the moving ring 3 and the end face of the graphite ring 2, thereby improving the sealing reliability and durability.
[0031] In summary, the inlay structure of the starter motor automatic sealing stationary ring assembly provided by this utility model eliminates the metal surrounding extending below the inner diameter of the graphite ring 2 in existing inlay structures by placing the metal ring 1 on the outer circumferential surface of the graphite ring 2 and on the side facing the wave spring 4. This allows for an axial thickening of the graphite ring 2 by 30%–50% and a radial thickening of 80%–100% within a 10mm axial length that remains unchanged, significantly improving the strength and crack resistance of the brittle graphite ring 2. Simultaneously, the inner diameter of the graphite ring 2 is provided with an annular groove, and the annular groove contains… The O-ring 9 forms a radial seal with the starter housing, replacing the traditional metal ring 1 transition seal. This reduces the number of leakage channels from three to two, completely eliminating the third leakage channel between the graphite ring 2 and the metal ring 1. This significantly reduces stress concentration and end face deformation, improving sealing reliability. In addition, there is no adhesive layer between the inner circumferential surface of the metal ring 1 and the outer circumferential surface of the graphite ring 2, allowing it to withstand temperatures above 300°C without adhesive. This achieves a long-life, zero-leakage dynamic seal under high-speed and high-temperature conditions in a confined space.
Claims
1. An embedded structure for a starter motor automatic sealing stationary ring assembly, characterized in that: The device includes a graphite ring (2), a metal ring (1), and a wave spring (4). The metal ring (1) is disposed on the outer circumferential surface of the graphite ring (2) and on the side facing the wave spring (4). The wave spring (4) is disposed on the metal ring (1) and a limiting tongue (7) is provided on the wave spring (4). The limiting tongue (7) is evenly disposed along the circumferential direction of the wave spring (4). An annular groove is provided on the inner circumferential surface of the graphite ring (2), and a sealing ring (9) is provided in the annular groove.
2. The embedded structure of the starter motor automatic sealing stationary ring assembly according to claim 1, characterized in that: The outer circumferential surface of the metal ring (1) is provided with an anti-rotation boss (8).
3. The embedded structure of the starter motor automatic sealing stationary ring assembly according to claim 1, characterized in that: The axial height of the limiting tongue (7) is less than the free height of the wave spring (4), and the axial height of the limiting tongue (7) is greater than the high pressure height of the wave spring (4).
4. The embedded structure of the starter motor automatic sealing stationary ring assembly according to claim 3, characterized in that: The height of the limiting tongue (7) is greater than the height of the tail of the graphite ring (2).
5. The embedded structure of the starter motor automatic sealing stationary ring assembly according to claim 4, characterized in that: The limiting tongue (7) is provided in four parts.
6. The embedded structure of the starter motor automatic sealing stationary ring assembly according to claim 1, characterized in that: The metal ring (1) and the graphite ring (2) are interference-fitted.