Small power turbine pre-pressing turbine pump with step-by-step driving by the side

Abstract

The application provides a small-power turbine by-pass type step-by-step driving pre-turbine pump, which comprises a shell assembly, and a rotor arranged in the shell assembly. The shell assembly comprises, from front to back along the axial direction, a pump inlet pipe, a flow guide shell, a pump outlet shell, a by-pass turbine shell and a turbine outlet shell which are connected in sequence. The rotor comprises an inducer coaxially arranged in the interior of the pump inlet pipe; the rotor comprises a main shaft, a front section of which is coaxially connected with the inducer; the by-pass turbine shell further coaxially sleeves a turbine, and a rear section of the main shaft is coaxially connected with the small-power turbine. An annular labyrinth groove is coaxially arranged on the disc of the small-power turbine, an inner side wall of the pump outlet shell coaxially sleeves a lining ring, the inner side wall of the lining ring is matched with the annular labyrinth groove, and a sealing expansion ring is arranged in the annular labyrinth groove. The small-power turbine can be driven by gas medium and also can be driven by liquid medium. The device shares the turbine for gas driving and liquid driving, and greatly simplifies the structure of the pre-turbine pump. The sealing expansion ring is adopted to ensure stable and reliable operation of the pre-turbine pump.

Description

Technical Field

[0001] This invention belongs to the field of turbomachinery technology, and relates to pre-compression turbopumps, specifically a low-power turbine-side-mounted step-drive pre-compression turbopump. Background Technology

[0002] Liquid rocket engines typically employ turbopump structures to pressurize the medium. To prevent cavitation of the main turbopump under relatively low tank pressure, a pre-pressurization turbopump is usually installed before the main turbopump for pre-pressurization. For upper-stage liquid rocket engines, a highly efficient pre-pressurization turbopump is typically used to start the main turbopump. Therefore, for upper-stage rocket engines with the above characteristics, a low-power pre-pressurization turbopump must simultaneously have the function of starting the main turbopump during the start-up phase and pre-pressurizing the main stage operating section.

[0003] The main components of a pre-pressure turbopump include an inducer, guide vane, turbine, nozzle, and housing. Existing pre-pressure turbopumps typically use a turbine-jacket type drive turbine, welded to the inducer rim, resulting in a relatively complex structure that affects rotor reliability. Furthermore, in schemes where the pre-pressure pump initiates the main turbopump's rotation, the starting turbine is driven by high-pressure gas, which is insoluble in the propellant in the pre-pressure pump's main flow path. Therefore, a separate starting turbine is required, along with an effective seal between the starting turbine and the pre-pressure pump to prevent backflow of driving gas into the pre-pressure pump's main flow path, which could lead to insufficient bearing cooling or rotor overspeed. Therefore, it is necessary to provide a simple and reliable pre-pressure turbopump structure to effectively initiate the main turbopump's rotation in the starting stage and pre-pressurize the main stage. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a low-power turbine-side-mounted step-drive pre-pressure turbine pump, thereby solving the technical problem that it is difficult to simultaneously reduce the structural complexity and improve the operational reliability of existing pre-pressure turbine pumps.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A low-power turbine-side-mounted step-drive pre-pressure turbine pump includes a housing assembly, within which a rotor is disposed.

[0006] The housing assembly, from front to back along the axial direction, includes a pump inlet pipe, a flow guide housing, a pump outlet housing, a side-mounted turbine housing, and a turbine outlet housing connected in sequence.

[0007] The rotor includes an inducer wheel, which is coaxially mounted inside the pump inlet pipe; the rotor also includes a main shaft, the front section of which is coaxially connected to the inducer wheel.

[0008] It also includes a small-power turbine, which is coaxially installed inside the side-mounted turbine housing; the rear axial section of the main shaft is coaxially connected to the small-power turbine, and the small-power turbine drives the inducer through the main shaft.

[0009] The small-power turbine's disc is also coaxially provided with multiple annular labyrinth grooves, which are evenly distributed along the axial direction. The pump outlet housing body is also coaxially provided with a bushing on the inner side wall near the axial rear end. The inner side wall of the bushing mates with the tooth tips of the multiple annular labyrinth grooves. Each annular labyrinth groove is also coaxially installed with a sealing expansion ring, which corresponds one-to-one with the annular labyrinth groove.

[0010] The low-power turbine can be driven by either a gaseous medium or a liquid medium, achieving step-by-step driving.

[0011] The present invention also has the following technical features: Specifically, the pump outlet housing includes a pump outlet housing body. Near the axial rear end of the pump outlet housing body, a turbine air inlet pipe and a turbine liquid inlet pipe are integrally formed, both arranged circumferentially. On the side wall of the pump outlet housing body near the axial rear end, a radially penetrating liquid nozzle and multiple radially penetrating gas nozzles are also provided. Each gas nozzle is connected to one end of the turbine air inlet pipe, and the other end of the turbine air inlet pipe is connected to the outside. Similarly, the liquid nozzle is connected to one end of the turbine liquid inlet pipe, and the other end of the turbine liquid inlet pipe is connected to the outside. The low-power turbine can be driven by the gas medium delivered through the turbine air inlet pipe and the multiple gas nozzles, and it can also be driven by the liquid medium delivered through the turbine liquid inlet pipe and the liquid nozzles, achieving step-by-step driving.

[0012] The liquid nozzle and multiple gas nozzles are arranged at the axial rear end of multiple sealing rings. The multiple sealing rings prevent the gas medium in the turbine intake pipe from backflowing to the axial front end of the low-power turbine.

[0013] Specifically, the "low power" refers to the maximum power P when a gas medium drives a low-power turbine. qmax ≤3.5kW; and the maximum power P when a small-power turbine is driven by a liquid medium. ymax ≤1.8kW.

[0014] Specifically, the shape of the guide shell is a concentric double-layered annular shell, with both axial ends of the guide shell open, and the axial front end face of the outer ring sidewall of the guide shell is fixedly connected to the axial rear end face of the pump inlet pipe.

[0015] A pump outlet pipe is integrally provided circumferentially on the outer side wall of the axial front section of the pump outlet housing body. The side wall of the pump outlet pipe is fixedly connected to the axial rear end face of the outer ring side wall of the guide housing, and the axial rear end face of the inner ring side wall of the guide housing is fixedly connected to the axial front end face of the pump outlet housing body.

[0016] The flow guide shell has flow guide blades installed in its annular cavity. The flow guide blades and the flow guide shell together form a flow guide. The rear axial end of the flow guide is connected to one end of the pump outlet pipe, and the other end of the pump outlet pipe is connected to the outside.

[0017] The axial front end of the flow guide is connected to the axial rear end of the inducer, the axial front end of the inducer is connected to the pump inlet pipe, and the axial front end of the pump inlet pipe is also connected to the outside.

[0018] The pump inlet pipe, inducer, guide vane, and pump outlet pipe constitute the main flow channel of the pump.

[0019] Specifically, the main spindle includes a main spindle body, and along the axial rear section of the main spindle body, auxiliary bearings and main bearings are coaxially mounted in sequence from front to back. The main bearings are located at the axial front end of the sealing expansion ring at the foremost end.

[0020] The main bearing is coaxially installed in the axial rear section of the pump outlet housing body, and the auxiliary bearing is coaxially installed in the inner cavity of the inner ring of the guide vane housing.

[0021] The main shaft body is also provided with multiple radially penetrating return holes, which are evenly distributed circumferentially and located between the main bearing and the low-power turbine.

[0022] Specifically, it also includes a sleeve, which includes an annular sleeve body and multiple radially penetrating guide holes on the sleeve body, which are evenly distributed circumferentially; multiple positioning grooves are also provided on the inner side wall of the sleeve body near the axial rear end, which are evenly distributed circumferentially.

[0023] The main spindle body is also provided with multiple keyways, which correspond one-to-one with the positioning slots. Positioning keys are also provided in the keyways, which correspond one-to-one with the keyways. The inner diameter of the sleeve body is equal to the outer diameter of the axial rear section of the main spindle body. The sleeve body is coaxially fitted on the axial rear section of the main spindle body. The sleeve body is arranged between the main bearing and the small power turbine.

[0024] The guide holes and return holes correspond one-to-one, and the inner diameter of the return hole is equal to the inner diameter of the guide hole. The return holes and guide holes are positioned by the positioning keys in the keyway and positioning groove to achieve coaxial arrangement. One end of each return hole is connected to one end of the corresponding guide hole, and the other end of each guide hole is connected to the axial rear end of the main bearing.

[0025] Specifically, the outer side wall of the axial front section of the main shaft body extends radially outward integrally with a guide slope. An axial gap is provided between the axial rear end face of the guide slope and the axial front end face of the inner ring side wall of the guide housing. The axial gap is arranged between the inducer wheel and the guide and is connected to the axial rear end of the inducer wheel.

[0026] The main shaft body is also coaxially provided with a throttling hole, which passes through the axial front end of the main shaft body. One end of the throttling hole is connected to the other end of each return hole, and the other end of the throttling hole is connected to the axial front end of the pump inlet pipe.

[0027] The pump inlet pipe, inducer, axial clearance, auxiliary bearing, main bearing, multiple guide holes, multiple return holes, and throttling holes constitute the bearing cooling channel.

[0028] Multiple sealing rings prevent the gas medium in the turbine intake pipe from backflowing into the pump main flow channel or the bearing cooling flow channel before the axial front end of the low-power turbine.

[0029] Specifically, the turbine outlet housing includes a turbine outlet housing body, which is a concentric double-layered annular shell. The axial front end of the turbine outlet housing body is open, and the axial rear end of the inner cavity of the inner ring of the turbine outlet housing body is closed. The annular cavity between the inner and outer rings of the turbine outlet housing body is the turbine outlet pipe inlet section. The axial rear end of the turbine outlet housing body is also fixedly connected circumferentially to a spiral worm-shaped turbine outlet pipe outlet section with a teardrop-shaped cross-section. One end of the turbine outlet pipe outlet section is connected to the axial rear end of the turbine outlet pipe inlet section, and the other end is connected to the outside.

[0030] The turbine outlet housing body is located at the axial rear end of the side-mounted turbine housing, and the axial front end of the turbine outlet pipe inlet section is connected to the axial rear end of the small-power turbine. The turbine inlet pipe, multiple gas nozzles, small-power turbine, turbine outlet pipe inlet section, and turbine outlet pipe outlet section form a turbine-driven gas flow channel. The turbine liquid inlet pipe, liquid nozzles, small-power turbine, turbine outlet pipe inlet section, and turbine outlet pipe outlet section form a turbine-driven liquid flow channel.

[0031] Specifically, the plurality of sealing expansion rings includes two beveled expansion rings and one straight expansion ring, with the straight expansion ring coaxially arranged in the middle of the two beveled expansion rings; each sealing expansion ring has an opening, and the assembly feature of the three sealing expansion rings is that the circumferential angle between the three openings is 120°.

[0032] The opening width a1 of the straight expansion ring is 0.1 to 0.2 mm, and the opening angle direction of the straight expansion ring is parallel to the radial direction of the straight expansion ring.

[0033] The opening width a2 of the two beveled expansion rings is 0.1 to 0.2 mm, and the angle γ between the opening angle direction of the two beveled expansion rings and the radial direction of the beveled expansion rings is 60°. The inner diameter of the two beveled expansion rings is equal to the inner diameter of the straight expansion ring, the outer diameter of the two beveled expansion rings is equal to the outer diameter of the straight expansion ring, and the axial length of the two beveled expansion rings is equal to the axial length of the straight expansion ring.

[0034] Specifically, the axial front end of the bushing extends beyond the axial front end of the foremost annular labyrinth groove, and the axial rear end of the bushing extends beyond the axial rear end of the last annular labyrinth groove.

[0035] The inner rear end of the bushing that mates with the multiple annular labyrinth grooves is also provided with a bushing assembly chamfer, and the chamfer angle β of the bushing assembly chamfer is 30° to 40°.

[0036] The radial clearance Y1 between the inner wall of the bushing and the tooth tips of the multiple annular labyrinth grooves is 0.15-0.2 mm, the radial clearance Y2 between the inner wall of the bushing and the outer wall of the three sealing expansion rings is 0-0.05 mm, and the radial clearance Y3 between the inner wall of the three sealing expansion rings and the bottom of the multiple annular labyrinth grooves is 0.15-0.35 mm.

[0037] The width b1 of each of the plurality of annular labyrinth grooves is 0.05 to 0.1 mm wider than the axial length b2 of each sealing ring.

[0038] Compared with the prior art, the present invention has the following technical effects: (I) The device in this invention can effectively start the main turbine pump during the startup phase and also pre-pressurize the main stage during the operating phase. The gas-driven and liquid-driven turbines share the same turbine, significantly simplifying the pre-pressurized turbine pump structure and avoiding the problem of each other being power-consuming components when the gas-driven and liquid-driven systems operate independently. The use of a sealing expansion ring solves the problem of difficulty in setting up a high-efficiency sealing structure in a small-sized structure, achieving bidirectional high-efficiency sealing during the step-by-step driving process and ensuring stable and reliable operation of the pre-pressurized turbine pump.

[0039] (II) The device in this invention is a turbine-side pre-compression turbine pump structure, characterized by low power and small size. The inducer and main shaft are designed as a single unit, and the rotor is supported by two radial bearings of the same type. The bearing closer to the turbine side is set as the main bearing, bearing the remaining axial force of the rotor, while the bearing closer to the pre-compression pump side is the auxiliary bearing. A single liquid nozzle and multiple gas nozzles are provided on the pump outlet housing. The liquid nozzle and gas nozzles can drive the same impact turbine. Multiple sealing expansion rings are provided between the turbine and the pump chamber, which can significantly improve the leakage throttling capacity between the turbine and the pump. Attached Figure Description

[0040] Figure 1 This is a cross-sectional schematic diagram of the overall structure of the device in this invention.

[0041] Figure 2 This is a schematic diagram of the structure of the liquid nozzle and the gas nozzle in the device of the present invention.

[0042] Figure 3 This is a schematic diagram of the sleeve structure in this invention.

[0043] Figure 4 for Figure 1 A scaled-up diagram of point H in the diagram.

[0044] Figure 5 This is a schematic diagram of the structure of a straight-mouthed expansion ring.

[0045] Figure 6 This is a proportionally enlarged structural diagram of the opening I of the straight expansion ring.

[0046] Figure 7 This is a schematic diagram of the oblique-shaped expansion ring.

[0047] Figure 8 This is a proportionally enlarged structural diagram of the opening J of the oblique expansion ring.

[0048] The labels in the diagram represent the following: 1-Housing assembly, 2-Rotor, 3-Small power turbine, 4-Annular labyrinth groove, 5-Ring liner, 6-Ring liner assembly chamfer, 7-Sealing expansion ring, 8-Pump main flow channel, 9-Auxiliary bearing, 10-Main bearing, 11-Sleeve, 12-Axial clearance, 13-Bearing cooling channel, 14-Locking key, 15-Turbine outlet pipe inlet section, 16-Turbine outlet pipe outlet section, 17-Turbine drive gas flow channel, 18-Turbine drive liquid flow channel.

[0049] 101-Pump inlet pipe, 102-Flow guide, 103-Pump outlet housing, 104-Side-mounted turbine housing, 105-Turbine outlet housing, 106-Turbine air inlet pipe, 107-Turbine liquid inlet pipe.

[0050] 201-Inducer wheel, 202-Main shaft, 203-Return hole, 204-Throttle hole.

[0051] 701 - Slanted expansion ring, 702 - Straight expansion ring.

[0052] 1101-Sleeve body, 1102-Guide hole, 1103-Positioning groove.

[0053] 10201 - Flow guide housing, 10202 - Flow guide blade.

[0054] 10301 - Pump outlet housing body, 10302 - Liquid nozzle, 10303 - Gas nozzle, 10304 - Pump outlet pipe.

[0055] 20201 - Spindle body, 20202 - Keyway, 20203 - Guide slope.

[0056] The specific content of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Detailed Implementation

[0057] It should be noted that, unless otherwise specified, all structures, components, equipment, materials and systems in this invention adopt structures, components, equipment, materials and systems commonly known in the art in the prior art. For example, the small power turbine adopts a known turbine, the sealing expansion ring adopts a known sealing expansion ring, the main bearing adopts a known main bearing, the auxiliary bearing adopts a known auxiliary bearing, the inducer adopts a known inducer, the guide vane adopts a known guide vane, and the engine system adopts a known engine system.

[0058] Following the above technical solution, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of the present invention fall within the protection scope of the present invention.

[0059] Example: This embodiment provides a low-power turbine-side-mounted, step-drive preload turbine pump, such as... Figure 1 As shown, it includes a housing assembly 1, and a rotor 2 is disposed inside the housing assembly 1.

[0060] The housing assembly 1 includes, from front to back along the axial direction, a pump inlet pipe 101, a flow guide housing 10201, a pump outlet housing 103, a side-mounted turbine housing 104, and a turbine outlet housing 105 connected in sequence.

[0061] The rotor 2 includes an inducer wheel 201, which is coaxially installed inside the pump inlet pipe 101; the rotor 2 also includes a main shaft 202, the front section of which is coaxially connected to the inducer wheel 201.

[0062] It also includes a small-power turbine 3, which is coaxially installed in the side-mounted turbine housing 104; the rear section of the main shaft 202 is coaxially connected to the small-power turbine 3, and the small-power turbine 3 drives the inducer wheel 201 through the main shaft 202.

[0063] The small-power turbine 3 also has multiple annular labyrinth grooves 4 coaxially formed on its wheel disc, and the multiple annular labyrinth grooves 4 are evenly distributed along the axial direction; a bushing 5 is also coaxially provided on the inner side wall of the pump outlet housing body 10301 near the axial rear end, and the inner side wall of the bushing 5 is engaged with the tooth top of the multiple annular labyrinth grooves 4. A sealing expansion ring 7 is also coaxially installed in each annular labyrinth groove 4, and the sealing expansion ring 7 corresponds one-to-one with the annular labyrinth groove 4.

[0064] The small-power turbine 3 can be driven by either a gaseous medium or a liquid medium, achieving step-by-step drive.

[0065] In this embodiment, the gas medium is a commonly known gas medium in the art, and the liquid medium is a commonly known liquid medium in the art.

[0066] In this embodiment, the low-power turbine 3 and rotor 2 are arranged side by side.

[0067] In this embodiment, the main shaft 202 and the inducer wheel 201 are designed as a coaxial whole, and the structure and design method of the inducer wheel 201 adopt the commonly known structure and design method in the art.

[0068] In this embodiment, the pump inlet pipe 101, the guide vane housing 10201, the pump outlet housing 103, and the side-mounted turbine housing 104 are welded together. The welding sequence is as follows: the 3D-printed, one-piece pump outlet housing 103 is electron-beam welded to the side-mounted turbine housing 104, further argon-arc welded to the guide vane housing 10201, and further argon-arc welded to the pump inlet pipe 101. The side-mounted turbine housing 104 and the turbine outlet housing 105 are bolted together. Both electron-beam welding and argon-arc welding employ commonly known welding methods in the art; the bolted connection employs commonly known bolted connection methods in the art.

[0069] In this embodiment, the pump inlet pipe 101 is made of a non-magnetic material to ensure effective measurement of the rotational speed of the inducer wheel 201; the non-magnetic material is a commonly used non-magnetic material known in the art.

[0070] In this embodiment, the bushing 5 and the pump outlet housing body 10301 are connected by electron beam welding, and the electron beam weld penetration depth L is ≥ 4 mm.

[0071] As a preferred embodiment of this invention, such as Figure 1 and Figure 2As shown, the pump outlet housing 103 includes a pump outlet housing body 10301. A turbine air inlet pipe 106 and a turbine liquid inlet pipe 107 are integrally formed on the outer side of the pump outlet housing body 10301 near its axial rear end. Both the turbine liquid inlet pipe 107 and the turbine air inlet pipe 106 are arranged circumferentially. A radially penetrating liquid nozzle 10302 and multiple radially penetrating gas nozzles 10303 are also provided on the side wall of the pump outlet housing body 10301 near its axial rear end. The multiple gas nozzles 10303 are all connected to... One end of the turbine intake pipe 106 is connected to the outside, and the other end of the turbine intake pipe 106 is connected to the outside. The liquid nozzle 10302 is connected to one end of the turbine liquid inlet pipe 107, and the other end of the turbine liquid inlet pipe 107 is connected to the outside. The small power turbine 3 can be driven by the gas medium delivered by the turbine intake pipe 106 and multiple gas nozzles 10303. The small power turbine 3 can also be driven by the liquid medium delivered by the turbine liquid inlet pipe 107 and liquid nozzles 10302, realizing step-by-step driving.

[0072] Liquid nozzle 10302 and multiple gas nozzles 10303 are arranged at the axial rear end of multiple sealing rings 7. The multiple sealing rings 7 prevent the gas medium in the turbine intake pipe 106 from backflowing to the axial front end of the small power turbine 3.

[0073] In this embodiment, the liquid nozzle 10302 and multiple gas nozzles 10303 can drive the same impact-type low-power turbine 3, avoiding the problem of the liquid medium driven turbine and the gas medium driven turbine being power-consuming components when they are set up independently. At the same time, it can greatly simplify the structure of the pre-pressure turbine pump, shorten the processing cycle, and improve the structural reliability.

[0074] As a preferred embodiment, "low power" refers to the maximum power P when the gas medium drives the low-power turbine 3. qmax ≤3.5kW; and the maximum power P when the liquid medium drives the small power turbine 3 ymax ≤1.8kW.

[0075] As a preferred embodiment, the shape of the guide housing 10201 is a concentric double-layer annular shell. Both axial ends of the guide housing 10201 are open, and the axial front end face of the outer ring sidewall of the guide housing 10201 is fixedly connected to the axial rear end face of the pump inlet pipe 101.

[0076] A pump outlet pipe 10304 is integrally provided circumferentially on the outer side wall of the axial front section of the pump outlet housing body 10301. The side wall of the pump outlet pipe 10304 is fixedly connected to the axial rear end face of the outer ring side wall of the guide housing 10201, and the axial rear end face of the inner ring side wall of the guide housing 10201 is fixedly connected to the axial front end face of the pump outlet housing body 10301.

[0077] A guide vane 10202 is provided in the annular cavity of the guide vane housing 10201. The guide vane 10202 and the guide vane housing 10201 constitute the guide vane 102. The rear end of the guide vane 102 is connected to one end of the pump outlet pipe 10304, and the other end of the pump outlet pipe 10304 is connected to the outside.

[0078] The axial front end of the flow guide 102 is connected to the axial rear end of the inducer wheel 201, the axial front end of the inducer wheel 201 is connected to the pump inlet pipe 101, and the axial front end of the pump inlet pipe 101 is also connected to the outside.

[0079] The pump inlet pipe 101, the inducer 201, the guide vane 102, and the pump outlet pipe 10304 constitute the main flow channel 8 of the pump.

[0080] In this embodiment, the flow guide 102 is 3D printed in one piece, and the flow guide blade 10202 is a cylindrical blade. The cylindrical blade adopts the commonly known cylindrical blade in the art. The number of cylindrical blades needs to avoid the first to third order harmonics of the number of outlet blades of the inducer wheel 201. The calculation method of the first to third order harmonics of the number of outlet blades of the inducer wheel 201 adopts the commonly known method in the art.

[0081] As a preferred embodiment, the spindle 202 includes a spindle body 20201. An auxiliary bearing 9 and a main bearing 10 are coaxially mounted on the axial rear section of the spindle body 20201 from front to back. The main bearing 10 is located at the axial front end of the sealing expansion ring 7 at the foremost end.

[0082] The main bearing 10 is coaxially installed in the axial rear section of the pump outlet housing body 10301, and the auxiliary bearing 9 is coaxially installed in the inner cavity of the inner ring of the guide housing 10201.

[0083] The main shaft body 20201 is also provided with multiple radially penetrating return holes 203. The multiple return holes 203 are evenly distributed along the circumference and are located between the main bearing 10 and the small power turbine 3.

[0084] As a preferred embodiment of this invention, such as Figure 3 As shown, it also includes a sleeve 11, which includes an annular sleeve body 1101. The sleeve body 1101 is also provided with a plurality of radially penetrating guide holes 1102, which are evenly distributed circumferentially. The inner sidewall of the sleeve body 1101 near the axial rear end is also provided with a plurality of positioning grooves 1103 along the axial direction, which are evenly distributed circumferentially.

[0085] The main spindle body 20201 is also provided with multiple keyways 20202, which correspond one-to-one with the positioning grooves 1103. Positioning keys 14 are also provided in the keyways 20202, which correspond one-to-one with the keyways 20202. The inner diameter of the sleeve body 1101 is equal to the outer diameter of the axial rear section of the main spindle body 20201. The sleeve body 1101 is coaxially fitted on the axial rear section of the main spindle body 20201. The sleeve body 1101 is arranged between the main bearing 10 and the small power turbine 3.

[0086] The guide hole 1102 corresponds one-to-one with the return hole 203. The inner diameter of the return hole 203 is equal to the inner diameter of the guide hole 1102. The return hole 203 and the guide hole 1102 are positioned by the keyway 20202 and the positioning key 14 in the positioning groove 1103 to achieve coaxial arrangement. One end of each return hole 203 is connected to one end of the corresponding guide hole 1102, and the other end of each guide hole 1102 is connected to the axial rear end of the main bearing 10.

[0087] As a preferred embodiment, the outer side wall of the axial front section of the main shaft body 20201 is integrally extended radially outward with a guide slope 20203. An axial gap 12 is provided between the axial rear end face of the guide slope 20203 and the axial front end face of the inner ring side wall of the guide housing 10201. The axial gap 12 is arranged between the inducer wheel 201 and the guide 102, and the axial gap 12 is connected to the axial rear end of the inducer wheel 201.

[0088] The main shaft body 20201 is also coaxially provided with a throttling hole 204. The throttling hole 204 passes through the axial front end of the main shaft body 20201. One end of the throttling hole 204 is connected to the other end of each return hole 203, and the other end of the throttling hole 204 is connected to the axial front end of the pump inlet pipe 101.

[0089] The pump inlet pipe 101, inducer 201, axial clearance 12, auxiliary bearing 9, main bearing 10, multiple guide holes 1102, multiple return holes 203, and throttling holes 204 constitute the bearing cooling channel 13.

[0090] Multiple sealing rings 7 prevent the gas medium in the turbine intake pipe 106 from backflowing into the pump main flow channel 8 before the axial front end of the low-power turbine 3 or into the bearing cooling flow channel 13.

[0091] In this embodiment, the number of throttling orifices 204 is 1, and the number of guide orifices 1102 and return orifices 203 are both 2.

[0092] In this embodiment, the cooling flow rate Qv of the liquid medium in the bearing cooling channel 13 is controlled by the throttling orifice 204 with the smallest flow area in the cooling circuit. The cooling flow rate Qv must be greater than the minimum cooling flow rate Q required by the auxiliary bearing 9 and the main bearing 10.min .

[0093] In this embodiment, the liquid medium transported in the pump main flow channel 8 and the liquid medium transported in the bearing cooling flow channel 13 are the same as the liquid medium transported in the turbine drive liquid flow channel 18. The gas medium driving the small-power turbine 3 in the turbine drive gas flow channel 17 is insoluble in the liquid medium driving the small-power turbine 3 in the turbine drive liquid flow channel 18.

[0094] As a preferred embodiment, the turbine outlet housing 105 includes a turbine outlet housing body, which is a concentric double-layered annular housing. The axial front end of the turbine outlet housing body is open, and the axial rear end of the inner cavity of the inner ring of the turbine outlet housing body is closed. The annular cavity between the inner and outer rings of the turbine outlet housing body is the turbine outlet pipe inlet section 15. The axial rear end of the turbine outlet housing body is also fixedly connected in the circumferential direction to a spiral worm-shaped turbine outlet pipe outlet section 16 with a teardrop-shaped cross-section. One end of the turbine outlet pipe outlet section 16 is connected to the axial rear end of the turbine outlet pipe inlet section 15, and one end of the turbine outlet pipe outlet section 16 is connected to the outside.

[0095] The turbine outlet housing body is located at the axial rear end of the side-mounted turbine housing 104, and the axial front end of the turbine outlet pipe inlet section 15 is connected to the axial rear end of the small-power turbine 3. The turbine inlet pipe 106, multiple gas nozzles 10303, small-power turbine 3, turbine outlet pipe inlet section 15, and turbine outlet pipe outlet section 16 form a turbine-driven gas flow channel 17. The turbine liquid inlet pipe 107, liquid nozzle 10302, small-power turbine 3, turbine outlet pipe inlet section 15, and turbine outlet pipe outlet section 16 form a turbine-driven liquid flow channel 18.

[0096] As a preferred embodiment of this invention, such as Figures 4 to 8 As shown, the multiple sealing expansion rings 7 include two beveled expansion rings 701 and one straight expansion ring 702, with the straight expansion ring 702 coaxially arranged in the middle of the two beveled expansion rings 701; each sealing expansion ring 7 is provided with an opening, and the assembly feature of the three sealing expansion rings 7 is that the circumferential angle between the three openings is 120°.

[0097] The opening width a1 of a straight expansion ring 702 is 0.1 to 0.2 mm, and the opening angle direction of the straight expansion ring 702 is parallel to the radial direction of the straight expansion ring 702.

[0098] The opening width a2 of the two beveled expansion rings 701 is 0.1 to 0.2 mm, and the angle γ between the opening angle direction of the two beveled expansion rings 701 and the radial direction of the beveled expansion rings 701 is 60°. The inner diameter of the two beveled expansion rings 701 is equal to the inner diameter of the straight expansion ring 702, the outer diameter of the two beveled expansion rings 701 is equal to the outer diameter of the straight expansion ring 702, and the axial length of the two beveled expansion rings 701 is equal to the axial length of the straight expansion ring 702.

[0099] In this embodiment, the assembly feature of the three sealing expansion rings 7 is that the circumferential angle between the three openings is 120°, so as to improve the throttling capacity of the three expansion rings seal.

[0100] As a preferred embodiment of this invention, such as Figure 4 As shown, the axial front end of the bushing 5 extends beyond the axial front end of the annular labyrinth groove 4 at the frontmost end, and the axial rear end of the bushing 5 extends beyond the axial rear end of the annular labyrinth groove 4 at the rearmost end.

[0101] The inner rear end of the inner wall of the bushing 5 that mates with the multiple annular labyrinth grooves 4 is also provided with a bushing assembly chamfer 6, and the chamfer angle β of the bushing assembly chamfer 6 is 30° to 40°.

[0102] The radial clearance Y1 between the inner wall of the bushing 5 and the tooth tips of the multiple annular labyrinth grooves 4 is 0.15 to 0.2 mm, the radial clearance Y2 between the inner wall of the bushing 5 and the outer walls of the three sealing expansion rings 7 is 0 to 0.05 mm, and the radial clearance Y3 between the inner walls of the three sealing expansion rings 7 and the bottom of the multiple annular labyrinth grooves 4 is 0.15 to 0.35 mm.

[0103] The width b1 of each of the multiple annular labyrinth grooves 4 is 0.05 to 0.1 mm wider than the axial length b2 of each sealing ring 7.

[0104] In this embodiment, the number of annular labyrinth grooves 4 is 3, and the structure of each annular labyrinth groove 4 is a square annular groove structure. The bottom of the square annular groove structure is cleaned to avoid local stress on the three sealing expansion rings 7. The cleaning method adopts a commonly known method in the art.

[0105] In this embodiment, the radial gap Y1 between the inner wall of the liner 5 and the tooth tips of the multiple annular labyrinth grooves 4 is 0.15 to 0.2 mm, which can ensure a certain sealing ability and at the same time avoid the liner 5 and the multiple annular labyrinth grooves 4 from rubbing against each other during operation.

[0106] In this embodiment, the relative sizes of radial clearance Y2, radial clearance Y3, and groove width b1 and axial length b2 are adapted to accommodate the assembly and effective operation of the three sealing rings 7.

[0107] In this embodiment, there is one liquid nozzle 10302, and the shape of the liquid nozzle 10302 is constricted from the outside to the inside along the radial direction of the pump outlet housing 103; there are eight gas nozzles 10303, and the eight gas nozzles 10303 are arranged together along the circumference of the pump outlet housing 103, and the shape of each gas nozzle 10303 is constricted and then expanded from the outside to the inside along the radial direction of the pump outlet housing 103.

[0108] In this embodiment, the axial front end of the foremost sealing ring 7 is the pre-pressure pump side, and the axial rear end of the last sealing ring 7 is the turbine side.

[0109] In this embodiment, the step-by-step drive principle and process of the pre-compression turbine pump are as follows: First, the start-up phase: High-pressure gas medium is introduced into the turbine-driven gas flow channel 17 through the turbine intake pipe 106 port, driving the small-power turbine 3 through multiple gas nozzles 10303. During start-up, it is necessary to ensure that there is no accumulated medium in the turbine outlet pipe inlet section 15 and the turbine outlet pipe outlet section 16 to avoid affecting the effective flow area of ​​the gas-driven outlet and the efficiency of the small-power turbine 3. During the start-up phase, the pressure P1 at the three sealing expansion rings 7 is greater than P2. P1 is the pressure of the liquid medium in the pre-pressure pump side pump main flow channel 8, and P2 is the pressure of the medium driving the small-power turbine 3 on the turbine side, i.e., the pressure of the gas medium. The three sealing expansion rings 7 effectively throttle the leakage of the medium from the pump leakage chamber, i.e., the pump main flow channel 8 and the bearing cooling flow channel 13, to the turbine side. The stable operating time during the start-up phase is determined by the engine system start-up characteristics.

[0110] Second, the overlapping working section: During the transition from the start-up stage to the main stage operating condition, there is a short-term overlapping working section between gas-driven and liquid-driven processes. A typical characteristic of this overlapping working section is that the small-power turbine 3 is driven by both gas and liquid, and its speed increases compared to the start-up stage. Since the outlet medium of the small-power turbine 3 during this overlapping working section is a mixture of gas-driven and liquid-driven media, and the outlet flow area remains unchanged, the pressure P2 on the turbine side at the three sealing rings 7 increases. The corresponding pressure difference at the three sealing rings 7 is P1 < P2, where P1 is the liquid medium in the main flow channel 8 of the pre-pressure pump side. The pressure of the medium is P2, which is the pressure of the medium driving the small-power turbine 3 on the turbine side, that is, the pressure of the mixed medium after the gas medium and the liquid medium are mixed. In order to control the gas medium driving the small-power turbine 3 from leaking to the pump side, it is necessary to ensure that (P2-P1) < 0.5MPa. If the pressure difference is too large, the amount of gas medium leaking to the pre-pressure pump side will increase. Since the gas medium driven by the gas is insoluble in the liquid medium in the main channel 8 of the pump, the excessive leakage of the gas medium will affect the cooling of the auxiliary bearing 9 and bearing 10 and the stable operation of the rotor 2. The overlap stable operation time is no more than 0.5s.

[0111] Third, the main stage operating condition: After the overlapping working section ends, the high-pressure gas medium drive path is closed, i.e., the turbine inlet pipe 106 is closed. Only the high-pressure liquid medium delivered by the liquid nozzle 10302 drives the small-power turbine 3 to do work. The liquid medium used for driving is the same as the liquid medium in the main flow channel 8 of the pump. After the liquid medium drive stabilizes, the pre-pressure pump enters the main stage operating condition. The speed in the main stage operating condition is lower than the speed in the start-up stage and the overlapping working section. The pressure at the three sealing expansion rings 7 is P1 > P2. P1 is the pressure of the liquid medium in the main flow channel 8 of the pre-pressure pump side, and P2 is the pressure of the liquid medium driving the small-power turbine 3 on the turbine side. The three sealing expansion rings 7 effectively achieve leakage throttling of the medium from the pump leakage chamber to the turbine side. The pre-pressure pump can operate in the main stage operating condition for a long time, and the operating time is determined by the flight mission requirements.

Claims

1. A low-power turbine-side-mounted step-drive preload turbine pump, comprising a housing assembly (1), wherein a rotor (2) is disposed within the housing assembly (1), characterized in that: The housing assembly (1) includes, from front to back along the axial direction, a pump inlet pipe (101), a flow guide housing (10201), a pump outlet housing (103), a side-mounted turbine housing (104), and a turbine outlet housing (105) connected in sequence. The rotor (2) includes an inducer wheel (201), which is coaxially installed inside the pump inlet pipe (101); the rotor (2) also includes a main shaft (202), the axial front section of which is coaxially connected to the inducer wheel (201); It also includes a small power turbine (3), and the small power turbine (3) is coaxially installed in the side-mounted turbine housing (104); the rear axial section of the main shaft (202) is coaxially connected to the small power turbine (3), and the small power turbine (3) drives the inducer wheel (201) through the main shaft (202); The small power turbine (3) is also provided with multiple annular labyrinth grooves (4) on the wheel disc, and the multiple annular labyrinth grooves (4) are evenly distributed along the axial direction; the pump outlet housing body (10301) is also provided with a bushing (5) on the inner side wall near the axial rear end, and the inner side wall of the bushing (5) is engaged with the tooth top of the multiple annular labyrinth grooves (4). Each annular labyrinth groove (4) is also provided with a sealing expansion ring (7) on the same axis, and the sealing expansion ring (7) corresponds one-to-one with the annular labyrinth groove (4); The low-power turbine (3) can be driven by a gas medium or a liquid medium, thus achieving step-by-step driving.

2. The low-power turbine-side-mounted, step-drive pre-compression turbine pump as described in claim 1, characterized in that, The pump outlet housing (103) includes a pump outlet housing body (10301). A turbine air inlet pipe (106) and a turbine liquid inlet pipe (107) are integrally provided on the outer side of the pump outlet housing body (10301) near its axial rear end. Both the turbine liquid inlet pipe (107) and the turbine air inlet pipe (106) are arranged circumferentially. A radially penetrating liquid nozzle (10302) and multiple radially penetrating gas nozzles (10303) are also provided on the side wall of the pump outlet housing body (10301) near its axial rear end. All gas nozzles (10303) are connected to the turbine air inlet pipe. One end of the air pipe (106) is connected to the outside, and the other end of the turbine air intake pipe (106) is connected to the outside. The liquid nozzle (10302) is connected to one end of the turbine liquid inlet pipe (107), and the other end of the turbine liquid inlet pipe (107) is connected to the outside. The small power turbine (3) can be driven by the gas medium delivered by the turbine air intake pipe (106) and multiple air nozzles (10303). The small power turbine (3) can also be driven by the liquid medium delivered by the turbine liquid inlet pipe (107) and the liquid nozzle (10302), thus realizing step-by-step driving. The liquid nozzle (10302) and multiple gas nozzles (10303) are arranged at the axial rear end of multiple sealing rings (7). The multiple sealing rings (7) prevent the gas medium in the turbine intake pipe (106) from backflowing to the axial front end of the small power turbine (3).

3. The low-power turbine-side-mounted, step-drive preload turbine pump as described in claim 2, characterized in that, The term "low power" refers to the maximum power P when a gas medium drives a low-power turbine (3). qmax ≤3.5kW; and the maximum power P when the liquid medium drives a small power turbine (3) ymax ≤1.8kW.

4. The low-power turbine-side-mounted, step-drive pre-compression turbine pump as described in claim 2, characterized in that, The shape of the flow guide housing (10201) is a concentric double-layer annular shell. Both axial ends of the flow guide housing (10201) are open. The axial front end face of the outer ring sidewall of the flow guide housing (10201) is fixedly connected to the axial rear end face of the pump inlet pipe (101). A pump outlet pipe (10304) is integrally provided circumferentially on the outer side wall of the axial front section of the pump outlet housing body (10301). The side wall of the pump outlet pipe (10304) is fixedly connected to the axial rear end face of the outer ring side wall of the guide housing (10201), and the axial rear end face of the inner ring side wall of the guide housing (10201) is fixedly connected to the axial front end face of the pump outlet housing body (10301). The flow guide housing (10201) has a flow guide blade (10202) installed in its annular cavity. The flow guide blade (10202) and the flow guide housing (10201) together form a flow guide (102). The rear end of the flow guide (102) is connected to one end of the pump outlet pipe (10304), and the other end of the pump outlet pipe (10304) is connected to the outside. The axial front end of the flow guide (102) is connected to the axial rear end of the inducer wheel (201), the axial front end of the inducer wheel (201) is connected to the pump inlet pipe (101), and the axial front end of the pump inlet pipe (101) is also connected to the outside. The pump inlet pipe (101), inducer (201), guide vane (102) and pump outlet pipe (10304) constitute the main flow channel (8) of the pump.

5. The low-power turbine-side-mounted, step-drive preload turbine pump as described in claim 4, characterized in that, The main shaft (202) includes a main shaft body (20201). The main shaft body (20201) is coaxially fitted with an auxiliary bearing (9) and a main bearing (10) along the axial direction from front to back. The main bearing (10) is located at the axial front end of the sealing expansion ring (7) at the front end. The main bearing (10) is coaxially installed in the axial rear section of the pump outlet housing body (10301), and the auxiliary bearing (9) is coaxially installed in the inner cavity of the inner ring of the guide housing (10201). The main shaft body (20201) is also provided with multiple radially penetrating return holes (203), which are evenly distributed along the circumference and are located between the main bearing (10) and the small power turbine (3).

6. The low-power turbine-side-mounted, step-drive preload turbine pump as described in claim 5, characterized in that, It also includes a sleeve (11), which includes an annular sleeve body (1101). The sleeve body (1101) is also provided with a plurality of radially penetrating guide holes (1102), which are evenly distributed in the circumferential direction. The sleeve body (1101) is also provided with a plurality of positioning grooves (1103) along the axial direction on the inner side wall near the axial rear end. The positioning grooves (1103) are evenly distributed in the circumferential direction. The main spindle body (20201) is also provided with multiple keyways (20202), which correspond one-to-one with the positioning grooves (1103). The keyways (20202) are also provided with positioning keys (14), which correspond one-to-one with the keyways (20202). The inner diameter of the sleeve body (1101) is equal to the outer diameter of the axial rear section of the main spindle body (20201). The sleeve body (1101) is coaxially fitted on the axial rear section of the main spindle body (20201). The sleeve body (1101) is arranged between the main bearing (10) and the small power turbine (3). The guide hole (1102) and the return hole (203) correspond one-to-one. The inner diameter of the return hole (203) is equal to the inner diameter of the guide hole (1102). The return hole (203) and the guide hole (1102) are positioned by the keyway (20202) and the positioning key (14) in the positioning groove (1103) to achieve coaxial arrangement. One end of each return hole (203) is connected to one end of the corresponding guide hole (1102), and the other end of each guide hole (1102) is connected to the axial rear end of the main bearing (10).

7. The low-power turbine-side-mounted, step-drive preload turbine pump as described in claim 6, characterized in that, The outer side wall of the axial front section of the main shaft body (20201) extends radially outward integrally with a guide slope (20203). An axial gap (12) is provided between the axial rear end face of the guide slope (20203) and the axial front end face of the inner ring side wall of the guide housing (10201). The axial gap (12) is arranged between the inducer wheel (201) and the guide (102). The axial gap (12) is connected to the axial rear end of the inducer wheel (201). The main shaft body (20201) is also coaxially provided with a throttling hole (204). The throttling hole (204) passes through the axial front end of the main shaft body (20201). One end of the throttling hole (204) is connected to the other end of each return hole (203), and the other end of the throttling hole (204) is connected to the axial front end of the pump inlet pipe (101). The pump inlet pipe (101), inducer (201), axial clearance (12), auxiliary bearing (9), main bearing (10), multiple guide holes (1102), multiple return holes (203) and throttling holes (204) constitute the bearing cooling channel (13). The multiple sealing rings (7) prevent the gas medium in the turbine intake pipe (106) from backflowing into the pump main flow channel (8) before the axial front end of the low-power turbine (3) or into the bearing cooling flow channel (13).

8. The low-power turbine-side-mounted step-drive preload turbine pump as described in claim 2, characterized in that, The turbine outlet housing (105) includes a turbine outlet housing body, which is a concentric double-layer annular housing. The front end of the turbine outlet housing body is open, and the rear end of the inner cavity of the inner ring of the turbine outlet housing body is closed. The annular cavity between the inner and outer rings of the turbine outlet housing body is the turbine outlet pipe inlet section (15). The rear end of the turbine outlet housing body is also fixedly connected in the circumferential direction to a turbine outlet pipe outlet section (16) with a spiral worm-like structure and a teardrop-shaped cross section. One end of the turbine outlet pipe outlet section (16) is connected to the rear end of the turbine outlet pipe inlet section (15), and the other end of the turbine outlet pipe outlet section (16) is connected to the outside. The turbine outlet housing body is arranged at the axial rear end of the side-mounted turbine housing (104), and the axial front end of the turbine outlet pipe inlet section (15) is connected to the axial rear end of the small power turbine (3); the turbine inlet pipe (106), multiple gas nozzles (10303), small power turbine (3), turbine outlet pipe inlet section (15) and turbine outlet pipe outlet section (16) form a turbine-driven gas flow channel (17); the turbine liquid inlet pipe (107), liquid nozzle (10302), small power turbine (3), turbine outlet pipe inlet section (15) and turbine outlet pipe outlet section (16) form a turbine-driven liquid flow channel (18).

9. The low-power turbine-side-mounted, step-drive preload turbine pump as described in claim 1, characterized in that, The plurality of sealing expansion rings (7) include two oblique expansion rings (701) and one straight expansion ring (702), with the straight expansion ring (702) coaxially arranged in the middle of the two oblique expansion rings (701); each sealing expansion ring (7) is provided with an opening, and the assembly feature of the three sealing expansion rings (7) is that the circumferential angle between the three openings is 120°; The opening width a1 of the straight expansion ring (702) is 0.1 to 0.2 mm, and the opening angle direction of the straight expansion ring (702) is parallel to the radial direction of the straight expansion ring (702); The opening width a2 of the two beveled expansion rings (701) is 0.1 to 0.2 mm, and the angle γ between the opening angle direction of the two beveled expansion rings (701) and the radial direction of the beveled expansion rings (701) is 60°. The inner diameter of the two beveled expansion rings (701) is equal to the inner diameter of the straight expansion ring (702), the outer diameter of the two beveled expansion rings (701) is equal to the outer diameter of the straight expansion ring (702), and the axial length of the two beveled expansion rings (701) is equal to the axial length of the straight expansion ring (702).

10. The low-power turbine-side-mounted, step-drive preload turbine pump as described in claim 1, characterized in that, The axial front end of the bushing (5) extends to the outer axial front end of the annular labyrinth groove (4) at the frontmost end, and the axial rear end of the bushing (5) extends to the outer axial rear end of the annular labyrinth groove (4) at the rearmost end. The inner rear end of the inner wall of the bushing (5) that cooperates with the multiple annular labyrinth grooves (4) is also provided with a bushing assembly chamfer (6), and the chamfer angle β of the bushing assembly chamfer (6) is 30° to 40°. The radial gap Y1 between the inner wall of the bushing (5) and the tooth tops of the multiple annular labyrinth grooves (4) is 0.15 to 0.2 mm, the radial gap Y2 between the inner wall of the bushing (5) and the outer wall of the three sealing expansion rings (7) is 0 to 0.05 mm, and the radial gap Y3 between the inner wall of the three sealing expansion rings (7) and the bottom of the multiple annular labyrinth grooves (4) is 0.15 to 0.35 mm. The width b1 of each of the multiple annular labyrinth grooves (4) is 0.05 to 0.1 mm wider than the axial length b2 of each sealing ring (7).

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