Turbine pump combined supporting flexible rotor structure of liquid rocket engine

Abstract

The invention relates to a turbopump combined supporting flexible rotor structure of a liquid-propellant rocket engine, and belongs to the technical field of liquid-propellant rocket engines. The invention relates to a flexible rotor structure of a liquid rocket engine with a secondary impeller and a secondary turbine disc. A rotor support is a combined structure of a hydrostatic bearing and a roller bearing; main radial loads are borne by the fluid hydrostatic bearing, the hydrostatic bearing is not abraded when working, the combined support of the fluid hydrostatic bearing and the roller bearing adapts to the working conditions of high rotating speed and high bearing DN value, the service life of the roller bearing is prolonged, the reuse frequency of the turbine pump is increased, and the manufacturing cost and the maintenance cost of the turbine pump are reduced. The required bearing capacity and rigidity range are obtained through design factors such as static pressure bearing structural design, pressure arrangement and gap design, the design is more flexible, the adaptability is wider, the structure is simpler, the economical efficiency is better, and the use maintainability is better.

Description

Technical Field

[0001] This invention belongs to the field of liquid rocket engine technology and relates to a flexible rotor structure supported by a liquid rocket engine turbopump combination. Background Technology

[0002] As liquid rocket engines strive for higher performance, higher thrust-to-weight ratio, lower cost, and reusability, turbopump speeds are increasing. Turbopump rotors are typically supported by roller bearings. The DN value of roller bearings limits further increases in turbopump speed. At the same time, the high-speed service life of roller bearings restricts the number of times the turbopump can be reused. For example, the SSME hydrogen-oxygen main turbopump requires bearing replacement after approximately 10 uses, extending the service life and increasing maintenance costs.

[0003] Based on international research and development experience, replacing traditional roller bearings with hydrostatic bearings in liquid rocket engine turbopumps is a development trend in order to improve turbopump speed and bearing life. Given that the use of hydrostatic bearings in domestic liquid rocket engines is currently lacking, there is an urgent need to conduct research on rotor shaft systems using hydrostatic bearings as the primary support in turbopumps. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a flexible rotor structure with combined support for a liquid rocket engine turbopump. It adopts a combination of hydrostatic bearings and roller bearings for support. The hydrostatic bearings are used as the main support for the rotor to bear the main radial load, while the roller bearings are set to bear the axial load during startup, so as to reduce the load on the roller bearings and improve the bearing service life.

[0005] The solution of the present invention is: a flexible rotor structure for supporting a liquid rocket engine turbopump combination, comprising: a turbine disk, roller bearings, a shaft, and an inducer, a first-stage impeller, a pump-end hydrostatic bearing, a second-stage impeller, and a turbine-end hydrostatic bearing sequentially sleeved on the shaft;

[0006] The turbine disk is a two-stage turbine disk structure, integrally formed with the shaft; The turbine end hydrostatic bearing is located between the second-stage impeller and the turbine disk, and is fixedly connected to the second pump housing, serving a supporting function. The hydrostatic bearing at the pump end is fixedly connected to the first pump housing and serves as a support. Roller bearings are installed inside the hydrostatic bearing at the pump end and serve a supporting function.

[0007] Furthermore, the turbine end hydrostatic bearing includes: a turbine hydrostatic bearing bushing and a turbine end hydrostatic bearing shell; The turbine hydrostatic bearing bushing has an inner wall that is rotatably connected to the shaft. The turbine end hydrostatic bearing bush and the turbine hydrostatic bearing sleeve form a dynamic and static kinematic pair of the turbine end hydrostatic bearing.

[0008] Furthermore, the turbine end hydrostatic bearing bush has a hollow structure and is sleeved on the outer wall of the turbine hydrostatic bearing bush, with the two connected by a gap; the second fixing member axially fixes the turbine end hydrostatic bearing bush to the second pump housing.

[0009] Furthermore, the turbine end hydrostatic bearing bush has several through-cavity structures evenly distributed along the circumference on the outer wall of the cavity structure; the through-cavity structure includes a concave cavity, a throttling orifice, and a liquid collecting cavity, which share a common central axis and are connected in sequence from the inside to the outside in the radial direction; the high-pressure cavity fluid flows into the low-pressure cavity through the through-cavity structure and the gap between the turbine hydrostatic bearing bush and the turbine end hydrostatic bearing bush in sequence.

[0010] Furthermore, the pump end hydrostatic bearing includes a pump end hydrostatic bearing bush and a pump end hydrostatic bearing shell. The pump end hydrostatic bearing bushing has an inner wall that is rotatably connected to the shaft. The pump end hydrostatic bearing bush and the pump end hydrostatic bearing sleeve form the pump end hydrostatic bearing dynamic and static kinematic pair.

[0011] Furthermore, the pump end hydrostatic bearing bush is a hollow columnar structure with a through hole at the bottom, which is fitted onto the end hydrostatic bearing bush; the outer wall of the columnar structure is provided with annular protrusions along the radial direction, and the first fixing member passes through the annular protrusions and the first pump housing in sequence to fix the two axially.

[0012] Furthermore, the roller bearing includes a roller bearing assembly, a support ring, and a cover plate; the roller bearing assembly is located inside the hollow cylindrical structure of the pump-end hydrostatic bearing bush; the support ring is disposed between the roller bearing assembly and the hollow cylindrical structure; the cover plate is a hollow annular structure, with its inner end contacting the outer ring of the roller bearing assembly, thus confining the support ring between the roller bearing assembly and the hollow cylindrical structure; its outer end is axially fixed to the outer wall of the hollow cylindrical structure of the pump-end hydrostatic bearing bush by a third fixing member.

[0013] Furthermore, the total eccentricity of the turbine end hydrostatic bearing and the pump end hydrostatic bearing is 0.3~0.7.

[0014] Furthermore, the working clearance of the turbine end hydrostatic bearing and the pump end hydrostatic bearing is 0.01~0.02mm.

[0015] Furthermore, the roller bearing is an angular contact ball bearing to accommodate the axial force requirements and move towards the turbine end.

[0016] The beneficial effects of this invention compared to the prior art are: This invention employs a combined support scheme of hydrostatic bearings and roller bearings. The hydrostatic bearings bear the main radial loads and do not experience wear during operation. The required load-bearing capacity and stiffness range are obtained through design factors such as the hydrostatic bearing structure design, pressure arrangement, and clearance design. The design is more flexible, adaptable, simpler in structure, more economical, and easier to use and maintain. The combined support of hydrostatic bearings and roller bearings significantly increases the adaptability to DN value working conditions, extends the service life of roller bearings, increases the number of times the turbine pump can be reused, and reduces the manufacturing and maintenance costs of the turbine pump. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the turbine pump assembly support rotor structure of the present invention; Figure 2 This is a schematic diagram of the hydrostatic bearing at the turbine end of the present invention; Figure 3 This is a schematic diagram of the turbine end hydrostatic bearing bush of the present invention; Figure 4 This is a schematic diagram of the hydrostatic bearing and roller bearing at the pump end of the present invention. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 As shown, a flexible rotor structure for a liquid rocket engine turbopump combination is provided, consisting of a second-stage impeller and a second-stage turbine disk 10. The rotor support is a combination of hydrostatic bearings and roller bearings. The turbine-end rotor support is a turbine-end hydrostatic bearing 6, located between the second-stage impeller 4 and the turbine disk 10. The turbine-end hydrostatic bearing 6 is fixed on the second pump housing 9. The pump-end rotor support is a pump-end hydrostatic bearing 5, located between the first-stage impeller 3 and the second-stage impeller 4. The pump-end hydrostatic bearing 5 is supported on the first pump housing 8, and a roller bearing 7 is provided at the pump end, located on the side of the pump-end hydrostatic bearing 5 close to the first-stage impeller 3.

[0020] The hydrostatic bearing 6 at the turbine end is introduced into the hydrostatic bearing inlet by the pump outlet fluid. One side of the outlet flows back to the inlet of the second stage impeller 4, and the other side leaks into the turbine cavity, providing a pressure differential for the hydrostatic bearing.

[0021] The hydrostatic bearing 5 at the pump end is introduced into the inlet of the hydrostatic bearing by the pump outlet fluid. One side of the outlet flows back to the inlet of the first stage impeller 3, and the other side leaks through the rotor opening and flows back to the inlet of the first stage impeller 3, providing the hydrostatic bearing pressure difference.

[0022] The roller bearing 7 uses a support ring design, and its support stiffness is lower than that of the hydrostatic bearing.

[0023] The stiffness of the turbine end hydrostatic bearing 6 is approximately 3 x 10⁻⁶.7 N / m, the stiffness of the hydrostatic bearing 5 at the pump end is approximately 2 x 10 N / m. 7 N / m, the stiffness of the support ring 702 of roller bearing 7 is approximately 1x10 N / m. 7 N / m.

[0024] Roller bearing 7 uses an angular contact ball bearing with a bevel on the left side and a dead point on the left end. During operation, it can move to the right to adapt to axial force requirements, so that it is not subjected to additional axial force during operation.

[0025] The rotor system operates at a speed of approximately 60,000 rpm, which is above the critical speed.

[0026] The working clearance of the turbine end hydrostatic bearing 6 and the pump end hydrostatic bearing 5 is approximately 0.01~0.02mm to provide suitable load-bearing capacity and stiffness.

[0027] The full-cycle working eccentricity of the turbine end hydrostatic bearing 6 and the pump end hydrostatic bearing 5 is approximately 0.3~0.7.

[0028] Nickel plating and other hard wear-resistant surface treatments are applied to the pump end hydrostatic bearing sleeve 501 and the turbine hydrostatic bearing sleeve 601 to improve the wear resistance of the start-up and shutdown sections.

[0029] like Figure 2 As shown, the turbine end hydrostatic bearing 6 includes: a turbine hydrostatic bearing bush 601, a turbine end hydrostatic bearing shell 602, and a first screw 603; the turbine hydrostatic bearing bush 601 is installed together with the rotor structure shaft 1, and together with the turbine end hydrostatic bearing shell 602, they form a turbine end hydrostatic bearing dynamic and static kinematic pair, wherein the turbine end hydrostatic bearing shell 602 is connected to the second pump housing 9 by the first screw 603.

[0030] The turbine end hydrostatic bearing bush 602 has a hollow structure and is sleeved on the outer wall of the turbine hydrostatic bearing bush 601. The hollow structure includes a ring and a cylindrical cavity, which are coincidentally connected as a whole. The first screw 603 passes through the ring and the second pump housing 9 in sequence to fix the two axially.

[0031] like Figure 3 As shown, the cavity wall of the turbine end hydrostatic bearing bush 602 has six through-cavities arranged radially. Each through-cavity includes a recess 604, a throttling orifice 605, and a liquid collecting chamber 606. These three structures share a central axis and are connected sequentially from the inside out radially. The throttling orifice 605 has a diameter of approximately 2 mm, the recess 604 has a length and width of approximately 15 mm, and a depth of approximately 1.5 mm. Fluid in the high-pressure chamber flows into the low-pressure chamber through the through-cavities and the gap between the turbine hydrostatic bearing bush 601 and the turbine end hydrostatic bearing bush 602.

[0032] like Figure 4 As shown, the pump-end hydrostatic bearing 5 includes a pump-end hydrostatic bearing bush 501, a pump-end hydrostatic bearing shell 502, and a second screw 503. The pump-end hydrostatic bearing bush 501 is installed together with the rotor structure shaft 1, and together with the pump-end hydrostatic bearing shell 502, forms a dynamic and static kinematic pair of the pump-end hydrostatic bearing. The pump-end hydrostatic bearing shell 502 is connected to the first pump housing 8 by the second screw 503.

[0033] The pump end hydrostatic bearing bush 502 is a hollow columnar structure with a through hole at its bottom end, which is fitted onto the end hydrostatic bearing bush 501. The outer wall of the columnar structure is provided with annular protrusions along the radial direction. The second screw 503 passes through the annular protrusions and the first pump housing 8 in sequence to fix the two axially.

[0034] The roller bearing 7 includes a roller bearing assembly 701, a support ring 702, a cover plate 703, and a third screw 704.

[0035] The roller bearing assembly 701 is located on the left side of the pump end hydrostatic bearing bush 501. It acts on the pump end hydrostatic bearing bush 502 through the support ring 702. It forms the rotor starting position with the outer ring of the roller bearing assembly 701 through the cover plate 703 and is fixed by the third screw 704.

[0036] The roller bearing assembly 701 is located inside the hollow cylindrical structure of the pump end hydrostatic bearing bush 502; the support ring 702 is disposed between the roller bearing assembly 701 and the hollow cylindrical structure; the cover plate 703 is a hollow ring structure, the inner end of which contacts the outer ring of the roller bearing assembly 701, limiting the support ring 702 between the roller bearing assembly 701 and the hollow cylindrical structure; the outer end of which is axially fixed to the outer wall of the hollow cylindrical structure of the pump end hydrostatic bearing bush 502 by a third screw 704.

[0037] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A flexible rotor structure supporting a liquid rocket engine turbopump combination, characterized in that, include: Turbine disk (10), roller bearing (7), shaft (1), and induction wheel (2), first stage impeller (3), pump end hydrostatic bearing (5), second stage impeller (4), turbine end hydrostatic bearing (6) sequentially fitted on shaft (1). The turbine disk (10) is a two-stage turbine disk structure, integrally formed with the shaft (1); The turbine end hydrostatic bearing (6) is located between the second stage impeller (4) and the turbine disk (10), and is fixedly connected to the second pump housing (9) to provide support. The pump end hydrostatic bearing (5) is fixedly connected to the first pump housing (8) and serves as a support; The roller bearing (7) is installed inside the hydrostatic bearing (5) at the pump end and serves as a support.

2. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 1, characterized in that: The turbine end hydrostatic bearing (6) includes: turbine hydrostatic bearing bush (601) and turbine end hydrostatic bearing shell (602). The turbine hydrostatic bearing bushing (601) has its inner wall rotatably connected to the shaft (1); The turbine end hydrostatic bearing bush (602) and the turbine hydrostatic bearing sleeve (601) form a dynamic and static kinematic pair of the turbine end hydrostatic bearing.

3. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 2, characterized in that: The turbine end hydrostatic bearing bush (602) has a hollow structure and is sleeved on the outer wall of the turbine hydrostatic bearing bush (601), with the two connected by a gap; the second fixing member (603) axially fixes the turbine end hydrostatic bearing bush (602) to the second pump housing (9).

4. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 3, characterized in that: The turbine end hydrostatic bearing bush (602) has several through-cavity structures evenly distributed along the circumference on the outer wall of the cavity structure; the through-cavity structure includes a concave cavity (604), a throttling hole (605), and a liquid collecting cavity (606), which share a common central axis and are connected in sequence from the inside to the outside in the radial direction; the high-pressure cavity fluid flows into the low-pressure cavity through the through-cavity structure and the gap between the turbine hydrostatic bearing bush (601) and the turbine end hydrostatic bearing bush (602).

5. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 1, characterized in that: The pump end hydrostatic bearing (5) includes a pump end hydrostatic bearing bush (501) and a pump end hydrostatic bearing shell (502). The pump end hydrostatic bearing bushing (501) has its inner wall rotatably connected to the shaft (1); The pump end hydrostatic bearing bush (502) and the pump end hydrostatic bearing sleeve (501) form a dynamic and static kinematic pair of the pump end hydrostatic bearing.

6. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 5, characterized in that: The pump end hydrostatic bearing bush (502) is a hollow columnar structure with a through hole at the bottom, which is fitted onto the end hydrostatic bearing bush (501). The outer wall of the columnar structure is provided with annular protrusions along the radial direction. The first fixing member (503) passes through the annular protrusions and the first pump housing (8) in sequence to fix the two axially.

7. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 6, characterized in that: The roller bearing (7) includes a roller bearing assembly (701), a support ring (702), and a cover plate (703). The roller bearing assembly (701) is located inside the hollow columnar structure of the pump end hydrostatic bearing bush (502). The support ring (702) is disposed between the roller bearing assembly (701) and the hollow columnar structure. The cover plate (703) is a hollow ring structure, with its inner end in contact with the outer ring of the roller bearing assembly (701), thus confining the support ring (702) between the roller bearing assembly (701) and the hollow columnar structure. Its outer end is axially fixed to the outer wall of the hollow columnar structure of the pump end hydrostatic bearing bush (502) by a third fastener (704).

8. The flexible rotor structure supporting a liquid rocket engine turbopump combination according to claim 1, characterized in that: The full-cycle working eccentricity of the turbine end hydrostatic bearing (6) and the pump end hydrostatic bearing (5) is 0.3~0.

7.

9. A flexible rotor structure supporting a liquid rocket engine turbopump assembly according to claim 1 or 8, characterized in that: The working clearance of the turbine end hydrostatic bearing (6) and the pump end hydrostatic bearing (5) is 0.01~0.02mm.

10. A flexible rotor structure supporting a liquid rocket engine turbopump assembly according to claim 1, characterized in that: The roller bearing (7) is an angular contact ball bearing, and the pump end moves towards the turbine end to meet the axial force requirements.

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