Elastic combined piston ring and squeeze film damper

Abstract

The present disclosure relates to an elastic combined piston ring and a squeeze film damper. Among them, the elastic combined piston ring includes: a first piston ring; a second piston ring axially attached to the first piston ring; a first spring; and a second spring. Wherein, on both sides of the fracture at the joint surface of the first piston ring, a first fracture installation groove is formed, and a first limiting groove is formed at the non-fracture part of the joint surface of the first piston ring. On both sides of the fracture at the joint surface of the second piston ring, a second fracture installation groove is formed, and a second limiting groove is formed at the non-fracture part of the joint surface of the second piston ring. The first spring is installed in the first limiting groove and the second fracture installation groove, and the second spring is installed in the second limiting groove and the first fracture installation groove. The limiting groove not only ensures that the spring cannot axially disengage from the fracture installation groove, but also the cooperation between the limiting groove and the spring can ensure that the installed spring can limit the relative rotation of the two piston rings in the circumferential direction, making it easy for the two piston rings to fit together and improving the sealing effect and damping effect.

Description

Technical Field

[0001] The present disclosure relates to an elastic combined piston ring and an squeeze film damper. Background Art

[0002] The statements herein only provide background information related to the present disclosure and do not necessarily constitute related art.

[0003] An squeeze film damper is a damper that effectively suppresses vibration by the squeezing and shearing actions of an oil film generated by the movement and radial movement of a damper journal (inner ring), and its squeeze film reduces vibration. When there is oil between two plates and they approach each other at a certain relative speed, due to the squeezing effect, a certain damping force will be generated between the two plates, forming a damping effect. Based on this principle, the squeeze film damper can absorb vibration energy, convert the vibration energy into heat energy, and the flowing squeeze oil takes away the heat. The squeeze film damper has been applied in aeroengines for a long time.

[0004] One of the core technologies of the squeeze film damper is the end sealing technology. Piston ring sealing is a commonly used sealing form. Under the action of its own elastic force, the outer circular surface of the piston ring presses against the outer ring of the oil film, thereby realizing the sealing of the outer circular surface of the piston ring. Since the outer circle of the piston ring and the inner circle of the outer ring of the oil film cannot be made exactly the same, the fitting degree and pressing degree at each part of the circumference are different, and it is difficult to achieve an ideal seal of the outer circular surface of the piston ring.

[0005] Figure 1 It is a schematic diagram of the pressure of the piston ring on the periphery in the related art. As Figure 1 shown, in the working state, the piston ring generates pressure on the periphery, and a good sealing effect is achieved through the pressure surface.

[0006] Figure 2 It is a schematic diagram of the free state and the tooling state of the piston ring in the related art. As Figure 2 shown, to generate pressure, before installation (in the free state), the piston ring has a larger radius of curvature, and after installation, pressure is generated through the deformation of the piston ring.

[0007] Figure 3 It is a schematic diagram of the structure of the piston ring and its inner support spring in the related art. As Figure 3 shown, to generate a larger sealing pressure, some inner support springs are arranged inside the piston ring.

[0008] Figure 4 It is a schematic diagram of the opening structure of a common form of piston ring. The piston ring has a break, and the interface form of the break is as Figure 4 shown. The break becomes the main leakage point of the seal leakage. Because there is only one break in the circumferential direction, the leakage from the break will also cause non-uniform leakage in the circumferential direction.

[0009] To improve the sealing performance of the outer circumferential surface of the piston ring, the related technology CN112178107A provides an extrusion oil film damper structure using a combined piston ring, and the sealing effect of the extrusion oil film damper piston of this structure is relatively good. However, since a spring is provided at the fracture and circumferential positioning is carried out using a boss, the positioning stability cannot be effectively guaranteed. Summary of the Invention

[0010] One technical problem to be solved by the present disclosure is to provide an elastic combined piston ring that can enhance the damping of the rotor system and reduce the vibration of the rotor when passing through the critical speed.

[0011] An elastic combined piston ring according to some embodiments of the present disclosure includes: a first piston ring; a second piston ring axially attached to the first piston ring; a first spring; and a second spring; wherein, first fracture mounting grooves are formed on both sides of the fracture of the fitting surface of the first piston ring, a first limiting groove is formed at the non-fracture of the fitting surface of the first piston ring, second fracture mounting grooves are formed on both sides of the fracture of the fitting surface of the second piston ring, a second limiting groove is formed at the non-fracture of the fitting surface of the second piston ring, the first spring is installed in the first limiting groove and the second fracture mounting groove, and the second spring is installed in the second limiting groove and the first fracture mounting groove.

[0012] In some embodiments, the groove depth of the first fracture mounting groove is greater than the groove depth of the second limiting groove, and the groove depth of the second fracture mounting groove is greater than the groove depth of the first limiting groove.

[0013] In some embodiments, the first piston ring and the second piston ring have the same structure, and the first spring and the second spring have the same structure.

[0014] In some embodiments, the length of the first limiting groove is greater than the working length of the first spring, and the length of the second limiting groove is greater than the working length of the second spring.

[0015] In some embodiments, the width of the first limiting groove is the same as the width of the second fracture mounting groove, the width of the second limiting groove is the same as the width of the first fracture mounting groove, the sum of the groove depth of the first fracture mounting groove and the groove depth of the second limiting groove is equal to the width of the first fracture mounting groove, and the sum of the groove depth of the second fracture mounting groove and the groove depth of the first limiting groove is equal to the width of the second fracture mounting groove.

[0016] In some embodiments, the width of the first fracture mounting groove is equal to the width of the second spring, and the width of the second fracture mounting groove is equal to the width of the first spring.

[0017] In some embodiments, the circumferential angle of the first fracture mounting groove to the first limiting groove in the circumferential direction of the first piston ring is configured to be 30° to 150°.

[0018] In some embodiments, the circumferential angle from the first fracture mounting groove to the first limiting groove is configured to be 90° in the circumferential direction of the first piston ring.

[0019] An oil film damper provided according to some embodiments of the present disclosure includes an oil film inner ring, an oil film outer ring, and the aforementioned elastic combined piston ring, and the elastic combined piston ring is installed in a piston ring mounting groove on the oil film inner ring.

[0020] In some embodiments, a chamfer is formed at the circumferentially outer side of the inner wall surface of the oil film outer ring, and the elastic combined piston ring is configured to have a diameter smaller than the outer circular edge diameter of the chamfer in the free state.

[0021] In some embodiments, the axial installation gap of the elastic combined piston ring in the piston ring mounting groove is smaller than the groove depth of the second limiting groove.

[0022] In the present disclosure, by providing a fracture mounting groove and a limiting groove on both the first piston ring and the second piston ring; the spring is installed in the fracture mounting groove and the limiting groove. Compared with the structural form of using a boss for circumferential limiting, the limiting groove not only ensures that the spring cannot axially disengage from the fracture mounting groove, but also the cooperation between the limiting groove and the spring can ensure that the installed spring can limit the relative rotation of the two piston rings in the circumferential direction, realizing the mutual circumferential limiting of the piston rings, facilitating the fitting of the two piston rings, improving the sealing effect and damping effect, and reducing the vibration when the rotor passes through the critical speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Schematic diagram of the pressure of the piston ring on the periphery in related technologies;

[0025] Figure 2 Schematic diagram of the free state and tooling state of the piston ring in related technologies;

[0026] Figure 3 Schematic diagram of the structure of the piston ring and its internal support spring in related technologies;

[0027] Figure 4 Schematic diagram of the piston ring opening structure in a common form;

[0028] Figure 5 Schematic diagram of the split structure according to some embodiments of the elastic combined piston ring of the present disclosure;

[0029] Figure 6 Schematic diagram of the combined structure according to some embodiments of the elastic combined piston ring of the present disclosure;

[0030] Figure 7 Schematic diagram of the structure at the fracture of the first piston ring according to some embodiments of the elastic combined piston ring of the present disclosure;

[0031] Figure 8 Schematic diagram of the structure of the first spring according to some embodiments of the elastic combined piston ring of the present disclosure;

[0032] Figure 9 Schematic diagram of the structural comparison of the elastic combined piston ring according to some embodiments of the present disclosure in the free state and the installed state;

[0033] Figure 10 Schematic diagram of the structure according to some embodiments of the squeeze film damper of the present disclosure.

[0034] Description of reference numerals

[0035] 1. Elastic combined piston ring; 2. Inner oil film ring; 3. Outer oil film ring; 11. First piston ring; 12. Second piston ring; 13. First fracture installation groove; 14. First limiting groove; 15. First spring; 16. Second fracture installation groove; 17. Second spring; 18. Second limiting groove; 21. Piston ring installation groove; 31. Chamfer. Detailed implementation manners

[0036] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and in no way limits the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments herein. These embodiments are provided to make the present disclosure thorough and complete and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, the compositions of materials, numerical expressions and values set forth in these embodiments should be construed as merely exemplary and not as limitations.

[0037] The "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different parts. Words such as "including" or "comprising" mean that the elements before this word cover the elements listed after this word, and do not exclude the possibility of also covering other elements. "Upper", "lower", "left", "right", etc. are only used to represent relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0038] In the present disclosure, when it is described that a specific device is located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When it is described that a specific device is connected to other devices, the specific device may be directly connected to the other devices without an intermediate device, or may not be directly connected to the other devices but have an intermediate device.

[0039] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as those, should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense, unless specifically defined as such herein.

[0040] Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the specification.

[0041] As Figure 5 and Figure 6 shown, an elastic combined piston ring 1 provided according to some embodiments of the present disclosure includes: a first piston ring 11, a second piston ring 12, a first spring 15, and a second spring 17; wherein, the first piston ring 11 and the second piston ring 12 are axially attached to each other; on both sides of the fracture at the mating surface of the first piston ring 11, a first fracture mounting groove 13 is formed, and at the non-fracture portion of the mating surface of the first piston ring 11, a first limiting groove 14 is formed. On both sides of the fracture at the mating surface of the second piston ring 12, a second fracture mounting groove 16 is formed, and at the non-fracture portion of the mating surface of the second piston ring 12, a second limiting groove 18 is formed. The first spring 15 is installed in the first limiting groove 14 and the second fracture mounting groove 16, and the second spring 17 is installed in the second limiting groove 18 and the first fracture mounting groove 13.

[0042] In this exemplary embodiment, by providing a first break mounting groove 13 and a first limiting groove 14 on the first piston ring 11, and a second break mounting groove 16 and a second limiting groove 18 on the second piston ring 12; the first spring 15 is installed in the first limiting groove 14 and the second break mounting groove 16, and the second spring 17 is installed in the second limiting groove 18 and the first break mounting groove 13. Compared with the structural form of using a boss for circumferential limiting, the arrangement of the first limiting groove 14 and the second limiting groove 18 not only ensures that the first spring 15 and the second spring 17 cannot axially disengage from the second break mounting groove 16 and the first break mounting groove 13 respectively, but also the cooperation between the first limiting groove 14 and the first spring 15, and the second limiting groove 18 and the second spring 17 can ensure that the installed first spring 15 and second spring 18 can limit the relative rotation of the first piston ring 11 and the second piston ring 12 in the circumferential direction, realizing the mutual circumferential limiting of the piston rings, facilitating the fitting of the two piston rings, and improving the sealing effect and damping effect.

[0043] Considering that the springs are mainly installed in the port mounting grooves, so that the springs provide tangential elastic force / pre-tightening force at the break, in some embodiments, the groove depth of the first break mounting groove 13 is greater than the groove depth of the second limiting groove 18, and the groove depth of the second break mounting groove 16 is greater than the groove depth of the first limiting groove 14. Combining Figure 5 and Figure 10 shown, the groove depth t2 of the first break mounting groove 13 is greater than the groove depth t3 of the second limiting groove 18.

[0044] For the convenience of installation and fitting and processing, in some embodiments, as Figure 5 and Figure 6 shown, the first piston ring 11 and the second piston ring 12 have the same structure, and the first spring 15 and the second spring 17 have the same structure.

[0045] To prevent the limiting groove from affecting the pre-tightening force of the spring acting on the break mounting groove, in some embodiments, the length of the first limiting groove 14 is greater than the working length of the first spring 15, and the length of the second limiting groove 18 is greater than the working length of the second spring 17. Combining Figure 5 and Figure 8 shown, taking the second spring 17 as an example, the length of the second limiting groove 18 is greater than the working length L1 of the second spring 17. It should be noted that the working length of the spring refers to the length of the spring in the pre-tightened state after the elastic combined piston ring 1 is installed as Figure 9 shown. As Figure 7 and Figure 9 shown, the length of the first break mounting groove 13 is L3, the piston ring closing gap is set as C, and L1 = 2L3 + C.

[0046] To ensure the installation stability, as Figure 5As shown, in some embodiments, the width of the first limiting groove 14 is the same as the width of the second fracture mounting groove 16, and the width of the second limiting groove 18 is the same as the width of the first fracture mounting groove 13, as Figure 10 shown, the sum of the groove depth of the first fracture mounting groove 13 and the groove depth of the second limiting groove 18 is equal to the width of the first fracture mounting groove 13, and the sum of the groove depth of the second fracture mounting groove 16 and the groove depth of the first limiting groove 14 is equal to the width of the second fracture mounting groove 16. That is, the cross-section of the closed mounting groove formed by the first limiting groove 14 and the second fracture mounting groove 16 is square, and the cross-section of the closed mounting groove formed by the second limiting groove 18 and the first fracture mounting groove 13 is also square.

[0047] Similarly, as Figure 8 and Figure 10 shown, in some embodiments, as shown, the width of the first fracture mounting groove 13 is equal to the width D of the second spring 17, and the width of the second fracture mounting groove 16 is equal to the width of the first spring 15.

[0048] To improve the limiting stability, as Figure 5 shown, in some embodiments, the circumferential angle of the first fracture mounting groove 13 to the first limiting groove 14 in the circumferential direction of the first piston ring 11 is configured to be 30° - 150°. In some embodiments, the circumferential angle of the first fracture mounting groove 13 to the first limiting groove 14 in the circumferential direction of the first piston ring 11 is configured to be 90° to obtain better limiting stability.

[0049] As Figure 10 shown, according to some embodiments of the present disclosure, an extrusion oil film damper includes an oil film inner ring 2 and the aforementioned elastic combined piston ring 1. The elastic combined piston ring 1 is installed between the oil film inner ring 2 and the oil film outer ring 3 and is located in the piston ring mounting groove 21 on the oil film inner ring 2. The remaining material thickness at the bottom of the fracture mounting groove is t1, and the remaining material thickness at the bottom of the limiting groove is t4. The width of the piston ring mounting groove can be slightly larger than the piston ring, so there is a side gap t5 between the piston ring and the piston ring mounting groove 21. The extrusion oil film damper correspondingly also has the above beneficial technical effects.

[0050] To facilitate the installation of the elastic combined piston ring 1, as Figure 10 shown, in some embodiments, a chamfer 31 is formed at the circumferential outer side of the inner wall surface of the oil film outer ring 3, and the elastic combined piston ring 1 is configured to have a diameter smaller than the outer circular edge diameter of the chamfer 31 in the free state. It should be noted that the elastic combined piston ring 1 in the free state means the state where the spring is in the natural length before installation.

[0051] As Figure 10As shown, in some embodiments, the axial installation clearance t5 of the elastic combined piston ring 1 in the piston ring installation groove 21 is smaller than the groove depth of the second limiting groove 18.

[0052] So far, the embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details well known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0053] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration and not for limiting the scope of the present disclosure. Those skilled in the art should understand that the above embodiments can be modified or some technical features can be equivalently replaced without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An elastic combined piston ring (1), characterized in that, Comprising: A first piston ring (11); A second piston ring (12) axially abutted against the first piston ring (11); A first spring (15); and A second spring (17); Wherein, a closed gap with a length of C is formed at the fracture of the first piston ring (11), first fracture mounting grooves (13) with a length of L3 are formed on both sides of the fracture at the joint surface of the first piston ring (11), a first limiting groove (14) is formed at the non-fracture part of the joint surface of the first piston ring (11), second fracture mounting grooves (16) are formed on both sides of the fracture at the joint surface of the second piston ring (12), and a second limiting groove (18) is formed at the non-fracture part of the joint surface of the second piston ring (12). The first spring (15) is installed in the first limiting groove (14) and the second fracture mounting grooves (16) so that the first spring (15) provides a pre-tightening force at the fracture of the joint surface of the first piston ring (11). The second spring (17) is installed in the second limiting groove (18) and the first fracture mounting grooves (13), and the working length L1 of the second spring (17) is equal to twice the length L3 of the first fracture mounting groove (13) plus the length C of the closed gap, so that the second spring (17) provides a pre-tightening force at the fracture of the joint surface of the second piston ring (12) with a working length of L1.

2. The elastic combined piston ring (1) according to claim 1, characterized in that, The groove depth of the first fracture mounting groove (13) is greater than the groove depth of the second limiting groove (18), and the groove depth of the second fracture mounting groove (16) is greater than the groove depth of the first limiting groove (14).

3. The elastic combined piston ring (1) according to claim 1, characterized in that, The first piston ring (11) and the second piston ring (12) have the same structure, and the first spring (15) and the second spring (17) have the same structure.

4. The elastic combined piston ring (1) according to claim 1, characterized in that, The length of the first limiting groove (14) is greater than the working length of the first spring (15), and the length of the second limiting groove (18) is greater than the working length of the second spring (17).

5. The elastic combined piston ring (1) according to claim 1, characterized in that, The width of the first limiting groove (14) is the same as the width of the second fracture mounting groove (16), the width of the second limiting groove (18) is the same as the width of the first fracture mounting groove (13), the sum of the groove depth of the first fracture mounting groove (13) and the groove depth of the second limiting groove (18) is equal to the width of the first fracture mounting groove (13), and the sum of the groove depth of the second fracture mounting groove (16) and the groove depth of the first limiting groove (14) is equal to the width of the second fracture mounting groove (16).

6. The elastic combined piston ring (1) according to claim 5, characterized in that, The width of the first fracture mounting groove (13) is equal to the width of the second spring (17), and the width of the second fracture mounting groove (16) is equal to the width of the first spring (15).

7. The elastic combined piston ring (1) according to claim 1, characterized in that, The circumferential angle of the first fracture mounting groove (13) to the first limiting groove (14) in the circumferential direction of the first piston ring (11) is configured to be 30° to 150°.

8. The elastic combined piston ring (1) according to claim 7, characterized in that, The circumferential angle of the first fracture mounting groove (13) to the first limiting groove (14) in the circumferential direction of the first piston ring (11) is configured to be 90°.

9. An squeeze film damper, characterized in that, It includes an inner oil film ring (2), an outer oil film ring (3), and the elastic combined piston ring (1) described in any one of claims 1 to 8. The elastic combined piston ring (1) is installed in a piston ring installation groove (21) on the inner oil film ring (2).

10. The squeeze film damper according to claim 9, characterized in that, A chamfer (31) is formed at the circumferential outer side of the inner wall surface of the outer oil film ring (3). The elastic combined piston ring (1) is configured such that its diameter in the free state is smaller than the outer circle diameter of the chamfer (31).

11. The squeeze film damper according to claim 9, wherein The axial installation clearance of the elastic combined piston ring (1) in the piston ring installation groove (21) is smaller than the groove depth of the second limiting groove (18).

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