阅读说明：本技术 一种液体火箭发动机涡轮泵用组合密封装置 (Combined sealing device for liquid rocket engine turbine pump ) 是由 黄丹 宋勇 庄宿国 孙浩 常涛 李志宇 周芮 于 2020-12-18 设计创作，主要内容包括：本发明涉及一种液体火箭发动机涡轮泵用组合密封装置,该装置包括液封轮、两瓣环组件、盖板；发动机启动前,位于液封轮侧的推进剂压力大于涡轮腔侧的压力,受涡轮泵介质入口压力的作用,两瓣环组件与盖板贴合形成密封面,用于阻止推进剂进入涡轮腔；发动机工作时,液封轮被转子带动旋转后产生的离心力将涡轮腔内液体沿径向抛出,从而将介质入口压力降低,液封轮的密封能力降低了作用于两瓣环组件上的液体压力,两瓣环组件与涡轮泵壳体配合面贴合,同时石墨环与转子之间零对零配合,阻止推进剂和燃气通过间隙相遇。该密封装置实现了发动机涡轮泵推进剂介质密封装置空间尺寸小,结构紧凑,多次起动,可重复使用的要求。(The invention relates to a combined sealing device for a turbo pump of a liquid rocket engine, which comprises a liquid seal wheel, two valve ring assemblies and a cover plate, wherein the liquid seal wheel is arranged on the liquid seal wheel; before the engine is started, the pressure of the propellant on the side of the liquid seal wheel is greater than the pressure on the side of the turbine cavity, and under the action of the medium inlet pressure of the turbine pump, the two valve ring assemblies are attached to the cover plate to form a sealing surface for preventing the propellant from entering the turbine cavity; when the engine works, the centrifugal force generated after the liquid seal wheel is driven by the rotor to rotate throws out liquid in the turbine cavity along the radial direction, so that the pressure of a medium inlet is reduced, the sealing capacity of the liquid seal wheel reduces the liquid pressure acting on the two valve ring assemblies, the two valve ring assemblies are attached to the matching surface of the turbine pump shell, and meanwhile, the graphite ring and the rotor are in zero-to-zero matching to prevent propellant and gas from meeting through a gap. The sealing device meets the requirements of small space size, compact structure, repeated starting and repeated use of the engine turbine pump propellant medium sealing device.)

1. A combined sealing device for a turbo pump of a liquid rocket engine is characterized by comprising a liquid seal wheel (1), two valve ring assemblies and a cover plate (2); an annular boss is arranged on the outer edge of the turbine pump shell (7) along the axial direction of the turbine rotating shaft, the outer edge of the cover plate (2) is fixedly connected with the annular boss of the turbine pump shell (7) through a screw (3), the inner edges of the turbine pump shell (7) and the cover plate (2) are in clearance fit with a turbine pump rotor, an annular gap is formed among the cover plate (2), the turbine pump shell (7) and the turbine pump rotor, and the two valve ring assemblies are positioned in the annular gap; the liquid seal wheel (1) is positioned on the other side of the turbine pump shell (7) opposite to the two valve ring assemblies, is fixedly arranged on an inner ring of a rotor bearing of the turbine pump and rotates along with a rotor of the turbine pump;

the two valve ring assemblies comprise graphite rings, anti-rotation pins and springs, the graphite rings are two semicircular rings before installation, and the two semicircular rings after installation are spliced into one graphite ring; the outer diameter side of the graphite ring is provided with a circle of arc grooves, the spring is installed in the arc grooves, meanwhile, the outer diameter side of the graphite ring is also provided with a pin hole, one end of an anti-rotation pin is inserted into the pin hole of the graphite ring and is excessively matched with the pin hole, the other end of the anti-rotation pin is connected with two hooks of the spring and is simultaneously inserted into a groove on a turbine pump shell (7), and the anti-rotation pin is matched with the turbine pump shell (7) and used for preventing the graphite ring from rotating and a cover plate from being abraded in the operation process; the spring provides an inward-contracting pretightening force for the graphite ring, the two semicircular rings tightly hoop the graphite ring on the rotor by the force of the spring, and the radial compensation capacity and the axial sealing capacity after the inner hole is abraded are realized in the operation process;

before the engine is started, the pressure of the propellant positioned on the side of the liquid seal wheel (1) is greater than the pressure on the side of the turbine cavity, and under the action of the medium inlet pressure of the turbine pump, the two valve ring assemblies are attached to the cover plate to form a sealing surface for preventing the propellant from entering the turbine cavity;

when the engine works, the centrifugal force generated after the liquid seal wheel is driven by the rotor to rotate throws out liquid in the turbine cavity along the radial direction, so that the pressure of a medium inlet is reduced, the sealing capacity of the liquid seal wheel reduces the liquid pressure acting on the two valve ring assemblies, the two valve ring assemblies are attached to the matching surface of the turbine pump shell (7), and meanwhile, the graphite ring and the rotor are in zero-to-zero matching to prevent propellant and gas from meeting through a gap.

2. The reusable combined sealing device for high speed and high pressure according to claim 1, characterized in that the hydraulic sealing wheel has one end face being a groove face facing the turbine pump housing (7) and the other end face being a back face facing the propellant cavity.

3. The reusable combined sealing device suitable for high speed and high pressure as claimed in claim 2, wherein the groove surface is provided with a plurality of grooves, and the shape of the groove is rectangular or oval.

4. The reusable combined sealing device suitable for high-speed and high-pressure as claimed in claim 2, wherein the groove surface is provided with a groove number Z ≧ 6.

5. The combined sealing device for the turbopump of the liquid rocket engine according to claim 1, wherein hooks at two ends of the spring are in clearance fit with the anti-rotation pins, and the clearance is less than or equal to 0.25 mm.

6. The reusable combined sealing device suitable for high speed and high pressure as claimed in claim 1, wherein: the matching surface of the liquid seal wheel and the rotor, the matching surface of the graphite ring and the cover plate, and the matching surface of the graphite ring and the shell ensure the air tightness through grinding, and the thickness after grinding is less than or equal to 0.1 mu m.

Technical Field

The invention relates to the technical field of sealing, is suitable for a turbopump of a liquid rocket engine, and particularly relates to a combined sealing device for the turbopump of the liquid rocket engine.

Background

In liquid rocket engines, the turbopump supplies the fuel and oxidant media required by the engine, and in order to ensure the reliable operation of the engine, corresponding sealing components are usually required to effectively isolate the propellant from meeting between the medium side of the engine pump and the turbine. High-temperature gas generated by fuel combustion in the turbine easily causes deformation of a sealing structure and vaporization of a medium, and influences effective sealing performance after operation of sealing. With the development of the liquid rocket engine technology, the development direction of the performance requirements on the rocket engine sealing assembly is mainly as follows: the variable working condition, the long service life, the high parameter, the reusability and the like, and the development of the adaptive sealing structure aiming at the characteristics also becomes the main research direction of the sealing design of the rocket engine.

Disclosure of Invention

The technical problem solved by the invention is as follows: the combined sealing device overcomes the defects that after the sealing structure in the prior art is repeatedly used for many times, the abrasion loss of a moving ring and a static ring is large, and the sealing function is invalid, and provides the combined sealing device for the turbopump of the liquid rocket engine so as to realize effective sealing after the sealing assembly is repeatedly used.

The technical scheme of the invention is as follows: a combined sealing device for a turbo pump of a liquid rocket engine comprises a liquid seal wheel, two valve ring assemblies and a cover plate; the outer edge of the turbine pump shell is provided with an annular boss along the axial direction of the turbine rotating shaft, the outer edge of the cover plate is fixedly connected with the annular boss of the turbine pump shell through screws, the inner edges of the turbine pump shell and the cover plate are in clearance fit with the turbine pump rotor, an annular gap is formed among the cover plate, the turbine pump shell and the turbine pump rotor, and the two valve ring assemblies are positioned in the annular gap; the liquid seal wheel is positioned on the other side of the turbine pump shell opposite to the two valve ring assemblies, is fixedly arranged on an inner ring of a rotor bearing of the turbine pump and rotates along with a rotor of the turbine pump;

the two valve ring assemblies comprise graphite rings, anti-rotation pins and springs, the graphite rings are two semicircular rings before installation, and the two semicircular rings after installation are spliced into one graphite ring; the anti-rotation pin is matched with the turbine pump shell and used for preventing the graphite ring from rotating and the cover plate from being abraded in the operation process; the spring provides an inward-contracting pretightening force for the graphite ring, the two semicircular rings tightly hoop the graphite ring on the rotor by the force of the spring, and the radial compensation capacity and the axial sealing capacity after the inner hole is abraded are realized in the operation process;

before the engine is started, the pressure of the propellant on the side of the liquid seal wheel is greater than the pressure on the side of the turbine cavity, and under the action of the medium inlet pressure of the turbine pump, the two valve ring assemblies are attached to the cover plate to form a sealing surface for preventing the propellant from entering the turbine cavity;

when the engine works, the centrifugal force generated after the liquid seal wheel is driven by the rotor to rotate throws out liquid in the turbine cavity along the radial direction, so that the pressure of a medium inlet is reduced, the sealing capacity of the liquid seal wheel reduces the liquid pressure acting on the two valve ring assemblies, the two valve ring assemblies are attached to the matching surface of the turbine pump shell, and meanwhile, the graphite ring and the rotor are in zero-to-zero matching to prevent propellant and gas from meeting through a gap.

One end face of the liquid seal wheel is a groove face, the groove face faces the turbine pump shell, the other end face of the liquid seal wheel is a back face, and the back face faces the propellant cavity.

The groove surface is provided with a plurality of grooves, and the grooves are rectangular or elliptical in shape.

The groove surface is provided with a groove number Z which is more than or equal to 6.

The hooks at the two ends of the spring are in clearance fit with the anti-rotating pins, and the clearance is less than or equal to 0.25 mm.

The matching surface of the liquid seal wheel and the rotor, the matching surface of the graphite ring and the cover plate, and the matching surface of the graphite ring and the shell ensure the air tightness through grinding, and the thickness after grinding is less than or equal to 0.1 mu m.

Compared with the prior art, the invention has the beneficial effects that:

(1) compared with the traditional integral sealing ring, the two-ring annular seal has the advantages that the spring is arranged on the outer diameter of the graphite ring in the operation process, the clamping effect is realized, and the radial compensation capacity and the axial sealing capacity after the inner hole is abraded are realized.

(2) The anti-rotation pin provided by the invention can prevent the graphite ring from rotating and the cover plate from being worn in the operation process.

(3) The invention is non-contact sealing, friction and abrasion of a friction pair are not involved in the operation process, the consistency of air tightness before and after the non-contact sealing operation is better, and zero abrasion can be realized on inner holes of two valve rings, so that the valve ring has good repeated use performance.

(4) The liquid seal wheel and the two valve rings are combined and sealed, and the liquid seal wheel is driven by the rotor to rotate to generate centrifugal force to throw out liquid along the radial direction, so that a good pressure reduction effect is achieved, and the high pressure resistance of the seal can be improved.

(5) The two valve ring assemblies divide the integral floating ring into two petals, and the integral floating ring is tightly hooped on the rotating shaft by the force of the hooping spring, so that the self-adaptability and the axial sealing capability of the floating ring in the operation process are improved.

(6) The anti-rotation pin and the sling spring prevent the rotation of the floating ring and realize the radial compensation after the inner hole is abraded, and have the advantages of long service life, stable performance, reusability and the like.

(7) The liquid seal wheel of the invention utilizes the blades to drive the propellant to rotate to generate radial centrifugal force so as to overcome the leakage of the propellant and ensure that a medium does not leak greatly in the starting and sliding stages of the engine.

Drawings

FIG. 1 is a schematic diagram of the overall structure of an embodiment of the present invention;

FIG. 2 is a structural diagram of a liquid seal wheel according to an embodiment of the present invention;

fig. 3 is a schematic view of a two-annulus assembly according to an embodiment of the invention.

Detailed Description

The invention is further illustrated by the following examples.

The invention provides a combined sealing device for a turbo pump of a liquid rocket engine, which comprises a liquid seal wheel 1, two valve ring assemblies and a cover plate 2; an annular boss is arranged on the outer edge of the turbine pump shell 7 along the axial direction of the turbine rotating shaft, the outer edge of the cover plate 2 is fixedly connected with the annular boss of the turbine pump shell 7 through a screw 3, an annular gap is formed among the cover plate 2, the turbine pump shell 7 and a turbine pump rotor, and the two valve ring assemblies are positioned in the annular gap; the liquid seal wheel 1 is positioned on the other side of the turbine pump shell 7 opposite to the two valve ring assemblies, is fixedly arranged on an inner ring of a rotor bearing of the turbine pump and rotates along with a rotor of the turbine pump;

the two valve ring assemblies comprise graphite rings, anti-rotation pins and springs, the graphite rings are two semicircular rings before installation, and the two semicircular rings after installation are spliced into one graphite ring; the outer diameter side of the graphite ring is provided with a circle of arc grooves, the spring is installed in the arc grooves, meanwhile, the outer diameter side of the graphite ring is also provided with a pin hole, one end of an anti-rotation pin is inserted into the pin hole of the graphite ring and is excessively matched with the pin hole, the other end of the anti-rotation pin is connected with two hooks of the spring and is simultaneously inserted into a groove on the turbine pump shell 7, and the anti-rotation pin is matched with the turbine pump shell 7 and is used for preventing the graphite ring from rotating and a cover plate from being abraded in the operation; the spring provides an inward-contracting pretightening force for the graphite ring, the two semicircular rings tightly hoop the graphite ring on the rotor by the force of the spring, and the radial compensation capacity and the axial sealing capacity after the inner hole is abraded are realized in the operation process;

before the engine is started, the pressure of the propellant positioned on the side of the liquid seal wheel 1 is greater than the pressure on the side of the turbine cavity, and under the action of the pressure of a medium inlet, the two valve ring assemblies are attached to the cover plate to form a sealing surface for preventing the propellant from entering the turbine cavity;

when the engine works, the centrifugal force generated after the liquid seal wheel is driven by the rotor to rotate throws out liquid in the turbine cavity along the radial direction, so that the pressure of a medium inlet is reduced, the sealing capacity of the liquid seal wheel reduces the liquid pressure acting on the two valve ring assemblies, the two valve ring assemblies are attached to the matching surface of the turbine pump shell 7, and meanwhile, the graphite ring and the rotor are in zero-to-zero matching to prevent the propellant and the fuel gas from meeting through a gap.

Preferably, one end face of the liquid seal wheel is a groove face, the groove face faces the turbo pump shell 7, the other end face is a back face, and the back face faces the propellant cavity.

Preferably, the groove surface is provided with a plurality of grooves, the number Z of the grooves is more than or equal to 6, and the grooves are rectangular or elliptical.

Preferably, the hooks at the two ends of the spring are in clearance fit with the anti-rotating pins, and the clearance is less than or equal to 0.25 mm.

Preferably, the matching surface of the liquid seal wheel and the rotor, the matching surface of the graphite ring and the cover plate, and the matching surface of the graphite ring and the shell ensure the sealing performance through grinding, and the thickness after grinding is less than or equal to 0.1 mu m.

Example 1

Referring to fig. 1 to 3, an embodiment of the present invention mainly comprises a liquid seal wheel (1), two valve ring assemblies, a cover plate (2), a screw (3), and a housing (7). As shown in figure 3, the two valve ring assemblies are composed of a graphite ring (4), a spring (5) and an anti-rotation pin (6). When the liquid seal wheel is used, the liquid seal wheel is fixedly arranged on an inner ring of a rotor bearing of the turbine pump and rotates along with a rotor of the turbine pump; the spring is arranged in an arc groove at the outer diameter of the graphite ring, one end of the anti-rotation pin is inserted into a pin hole of the graphite ring and is in excessive fit with the pin hole, and the other end of the anti-rotation pin connects two hooks of the spring and is simultaneously inserted into a groove on the shell of the turbine pump; the outer edge of the cover plate is fixedly connected with an annular boss of the turbine pump shell through a screw. One end of the liquid seal wheel with the groove faces the side of the turbine cavity, the rotor rotates to drive the liquid seal wheel to rotate, and the generated centrifugal force throws out liquid along the radial direction, so that the pressure of the medium inlet is reduced by 95-100%. As shown in fig. 2, the cross section of the liquid seal wheel groove may be rectangular or elliptical. The number of the grooves Z is more than or equal to 6.

As shown in fig. 3, the graphite ring in the two valve ring assemblies is divided into two segments before installation, the outer circle of the graphite ring is provided with a circular arc groove for installing a spring, and the spring is used for tightly clamping the graphite ring divided into two segments on the rotor. Meanwhile, in the operation process, in order to prevent the graphite ring from rotating along with the rotation of the rotor and the matched cover plate or the shell, a hole is formed in the outer circle of the graphite ring and is excessively matched with the anti-rotation pin, and the gap is less than or equal to 0.03 mm. One end of the anti-rotation pin is inserted into the hole of the excircle of the graphite ring, and the other end of the anti-rotation pin is inserted into the anti-rotation groove on the shell. The two ends of the spring for tightly hooping the graphite ring are respectively provided with a hook, and the two hooks are sleeved on the anti-rotation pins in clearance fit, and the clearance is less than or equal to 0.25 mm.

The two end faces of the graphite ring and the sealing surface on the cover plate shell matched with the graphite ring are ground, and before the engine is started, the graphite ring and the sealing surface of the cover plate play a main sealing role and are used for isolating a propellant from entering a turbine cavity; when the engine works, the side pressure of the turbine is higher than the side pressure of the medium under the sealing action of the liquid sealing wheel, so that the graphite ring and the sealing surface of the shell play a main sealing role. And meanwhile, zero-to-zero matching is realized between the graphite ring and the rotor, so that the propellant and the fuel gas are prevented from meeting through a gap.

The working principle of the invention is as follows: when the combined seal works, the sealing cavity is filled with high-pressure medium, and the liquid seal wheel is driven by the rotor to rotate to generate centrifugal force to throw out liquid along the radial direction, so that the combined seal has a sealing effect. In operation, the sealing capability of the hydraulic sealing wheel can reduce the hydraulic pressure acting on the two valve ring assemblies.

The two valve ring assemblies further isolate propellant and fuel gas, before the engine is started, the engine is jointed with the cover plate to form a sealing surface under the action of medium inlet pressure, and fuel is prevented from entering a turbine cavity; after the engine is started, the liquid seal wheel reduces the pressure of a medium inlet, the side pressure of the turbine is higher at the moment, and the two valve ring assemblies are attached to the matching surface of the pump shell body to prevent gas from entering the fuel cavity.

The two valve rings divide the graphite ring into two valve halves, the graphite ring is tightly hooped on the rotor by the force of the spring, and the two valve rings have radial compensation capability and axial sealing capability after inner holes are abraded in the operation process. The anti-rotation pin can prevent the graphite ring from rotating and the cover plate from being abraded in the operation process.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.