A tool and method for machining matching holes of a liquid rocket engine turbo pump shaft system

Abstract

The present invention discloses a tool for machining matching holes in the shaft system of a liquid rocket engine turbine pump, comprising an outer male mold, an inner female mold, and a faceplate base; the inner splines of the outer male mold have the same shape as the splines of the turbine disk; the outer splines of the inner female mold have the same shape as the splines of the shaft; and the faceplate base is provided with an angular positioning reference. The present invention also discloses a method for machining matching holes in the shaft system of a liquid rocket engine turbine pump, comprising: fixing the inner female mold to the faceplate base; embedding the outer male mold on the outside of the inner female mold, and providing an angular positioning reference on the faceplate base; machining a through hole in the outer male mold based on the angular positioning reference; placing the outer male mold on the outside of the shaft, and machining a first matching hole at a position on the shaft corresponding to the through hole; placing the turbine disk on the outside of the inner female mold, and machining a second matching hole on the turbine disk based on the angular positioning reference. The present invention can achieve separate machining and forming of the matching holes of the shaft and the turbine disk, and the resulting shaft and turbine disk can be arbitrarily matched.

Description

Technical Field

[0001] The present invention belongs to the technical field of liquid rocket engine assembly process, and relates to various process methods for processing matching holes through spline positioning. The present invention can be used for processing matching holes in various other mechanical processes, and particularly relates to a tool and method for processing matching holes in a liquid rocket engine turbine pump shaft system. Background Art

[0002] Currently, in the assembly of liquid rocket engine turbopumps, the turbine impeller and shaft are mated via splines to transmit torque, and the axial direction is fixed to the shaft via bolts at the shaft end. The circumferential relationship between the spline teeth and the bolt holes is uncertain during machining of the shaft or turbine impeller. Therefore, the shaft and turbine impeller must be assembled together via a docking spline before the bolt holes are machined. This has the following drawbacks: First, the shaft is a slender structure, and the turbine impeller assembly on the shaft requires a complex set of tooling to secure the turbine impeller during bolt hole machining (no movement of the turbine impeller is allowed). The tooling used in actual production is large (wrapping the shaft), heavy, and complex to use. The clamping process is difficult, and the required machine tool travel is long. Second, the matched shaft and turbine impeller must be used in pairs. Replacing either one requires reassembly, which is not conducive to assembly. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects and provide a tool and method for processing the matching holes of the shaft system of a liquid rocket engine turbine pump, which solves the problem that the existing process for processing the matching holes after the assembly of the shaft and the turbine impeller is complicated and difficult to operate, and the technical problem that the processed products can only be used in pairs, which is not conducive to assembly. The present invention can realize the separate processing and forming of the matching holes of the shaft and the turbine impeller, and the obtained shaft and turbine impeller can be matched arbitrarily.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A tool for machining matching holes of a liquid rocket engine turbo pump shaft system, comprising an outer male mold, an inner female mold and a faceplate base;

[0006] The outer sleeve male mold is a cylindrical structure with an open first end. The outer sleeve male mold is provided with an internal spline. The internal spline has the same specifications and structure as the spline of the turbine wheel.

[0007] The embedded female mold is a columnar structure, and the second end of the embedded female mold is provided with an external spline, and the specification and structure of the external spline are the same as those of the shaft spline;

[0008] The faceplate base is fixedly mounted on the machine platform. The faceplate base is used to connect to the first end of the embedded female mold. An angular positioning reference is provided on the faceplate base.

[0009] When the outer sleeve male mold is sleeved on the outside of the second end of the embedded female mold, a through hole is machined on the second end of the outer sleeve male mold based on the angular positioning reference; when the outer sleeve male mold is sleeved on the outside of the shaft, a first matching hole is machined at a position on the shaft corresponding to the through hole;

[0010] When the turbine wheel disc is sleeved on the outside of the second end of the embedded female mold, a second matching hole is machined on the turbine wheel disc based on the angular positioning reference;

[0011] The first matching hole and the second matching hole are used to realize the bolt connection between the turbine wheel and the shaft.

[0012] Furthermore, it also includes a tightening bolt;

[0013] A bolt hole is provided at the center of the second end of the outer sleeve male mold, and the tightening bolt passes through the bolt hole and is fixedly connected to the embedded female mold or shaft, thereby achieving the tightening of the outer sleeve male mold and the embedded female mold or shaft.

[0014] A method for machining a matching hole for a liquid rocket engine turbo pump shaft system is implemented using the aforementioned tooling for machining matching holes for a liquid rocket engine turbo pump shaft system, comprising:

[0015] S1 installs the faceplate base on the machine platform;

[0016] The first end of the embedded female mold is fixedly connected to the faceplate base;

[0017] Install the outer male mold on the outer side of the second end of the inner female mold, and press the outer male mold and the inner female mold tightly;

[0018] S2 sets the angular positioning reference on the faceplate base;

[0019] S3 processes a through hole at the second end of the outer sleeve male mold based on the angular positioning reference;

[0020] S4: removing the outer sleeve male mold from the inner sleeve female mold; putting the outer sleeve male mold on the outside of the shaft, pressing the outer sleeve male mold and the shaft tightly, and then machining a first matching hole at a position on the shaft corresponding to the through hole;

[0021] S5: The turbine wheel disc is placed on the outside of the second end of the embedded female mold, and after the turbine wheel disc and the embedded female mold are pressed tightly, a second matching hole is processed on the turbine wheel disc based on the angular positioning reference.

[0022] Furthermore, there are four first matching holes and four second matching holes.

[0023] Furthermore, in step S1, the method of fixing the first end of the embedded female mold to the faceplate base includes:

[0024] Connect the embedded female mold to the faceplate base through hexagonal bolts, and process a first positioning pin hole and a second positioning pin hole on the embedded female mold and the faceplate base respectively;

[0025] Grind the locating pin so that the locating pin has a clearance fit with the first locating pin hole and an interference fit with the second locating pin hole;

[0026] The clearance of clearance fit is 0.01~0.02mm, and the interference of interference fit is 0.01~0.02mm.

[0027] The pin hole is provided to ensure that the angular positioning reference on the faceplate base is unique to the circumferential position of the spline.

[0028] Furthermore, a bolt hole is provided at the center of the second end of the outer sleeve male mold, and the clamping bolt passes through the bolt hole and is fixedly connected to the embedded female mold or shaft, thereby achieving compression between the outer sleeve male mold and the embedded female mold or shaft.

[0029] Furthermore, in step S5, the turbine wheel disc and the embedded female mold are pressed together using a pressure plate, a tie rod assembly, and a push rod assembly; the tie rod assembly includes a tie rod and a hexagonal shoulder nut, and the push rod assembly includes a push rod and a push block;

[0030] The pressure plate is located above the turbine wheel;

[0031] The lower end of the pull rod is connected to the disc base through a T-shaped block, and the upper end of the pull rod passes through the pressure plate upward and presses the upper surface of the pressure plate through a hexagonal shoulder nut; the lower end of the push rod is connected to the disc base through a T-shaped block, and the upper end of the push rod is supported on the lower surface of the pressure plate through the push block.

[0032] Furthermore, the distance between the push rod and the axis of the turbine wheel is greater than the distance between the pull rod and the axis of the turbine wheel;

[0033] Under the action of the pressing force and the supporting force on the pressing plate, the pressing plate, the turbine wheel and the faceplate base are parallel.

[0034] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0035] (1) The present invention utilizes the substitutability of spline fitting to provide an efficient and stable method for rapid processing of liquid rocket engine shaft matching holes, avoiding the disadvantage of traditional methods that matching products must be assembled together before processing, reducing the difficulty of processing liquid rocket engine turbopump shaft matching holes, improving product production consistency and safety, and solving the problem that matching parts need to be matched and shipped multiple times, and must be one-to-one combined after punching and cannot be freely matched;

[0036] (2) The tooling structure of the present invention is simple, and the assembly process is decomposed into the parts processing process. The parts are processed and formed once without repeated processing. The method is practical and can be adapted to various types of liquid rocket engine turbine pump shaft parts with punching processing, and is suitable for industrialized and standardized production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention is equipped with a punching tool assembly diagram;

[0038] Figure 2 This is the assembly drawing of the shaft end matching hole processing of the present invention;

[0039] Figure 3 This is the assembly drawing of the turbine wheel disc matching hole processing of the present invention;

[0040] Figure 4 This is an assembly diagram of the shaft and turbine wheel of the present invention;

[0041] Figure 5 This is a schematic diagram of the angular position reference of the present invention;

[0042] In the figure, 1-tightening bolt, 2-outer male mold, 3-embedded female mold, 4-locating pin, 5-hexagonal bolt, 6-disc base, 7-eye screw, 8-shaft, 9-hexagonal shoulder nut, 10-pressure plate, 11-turbine impeller, 12-top block, 13-cone-end tightening screw, 14-top rod, 15-pull rod, 16-T-block. DETAILED DESCRIPTION

[0043] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0044] The word "exemplary" is used exclusively herein to mean "serving as an example, example, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0045] The present invention overcomes the shortcomings of the prior art in that the processing of the matching holes after the shaft and the turbine wheel are assembled is complicated, the operation is difficult, and the products can only be used in pairs after processing, which is not conducive to assembly. It provides a process equipment for assembling and punching through the conversion of the female mold and the male mold, so that the matching holes of the shaft and the turbine wheel are formed in their respective processing steps, and at the same time, the processed shaft and the turbine wheel can be matched arbitrarily.

[0046] On the one hand, the present invention provides a liquid rocket engine turbine pump shaft system matching hole processing tooling, including a tightening bolt 1, an outer sleeve male mold 2, an embedded female mold 3, a locating pin 4, a hexagonal bolt 5, a disc base 6, a lifting eye screw 7, a hexagonal shoulder nut 9, a pressure plate 10, a top block 12, a tapered end tightening screw 13, a push rod 14, a pull rod 15, and a T-shaped block 16. The internal spline structure and specifications of the outer sleeve male mold 2 are the same as those of the turbine impeller 11, and the external spline structure and specifications of the embedded female mold 3 are the same as those of the shaft 8. That is, the present invention replaces the spline matching structure of the turbine impeller 11 and the shaft 8 by the outer sleeve male mold 2 and the embedded female mold 3 through a substitution method.

[0047] Another aspect of the present invention provides a method for machining a matching hole in a liquid rocket engine turbopump shaft system, comprising:

[0048] The drilling jig replacement method is used to process the mating holes that need to be processed after the shaft 8 and the turbine impeller 11 are assembled together on a single part, that is, the outer sleeve male mold 2 is used to replace the turbine impeller 11 to drill holes on the shaft 8, and the embedded female mold 3 is used to replace the shaft 8 to drill holes on the turbine impeller 11. At the same time, an identifiable angular positioning reference that can determine the position relationship of the mating holes is designed on the spline of the outer sleeve male mold 2 to ensure that the mating holes are in the correct position after the shaft 8 and the turbine impeller 11 are assembled.

[0049] The outer sleeve male mold 2 is splined onto the inner female mold 3 and secured with compression bolts 1. The faceplate base 6 is fixed to the machine tool and aligned with the pre-set circumferential positioning reference. A mating hole 4-ΦD is machined on the end face of the outer sleeve male mold 2, serving as an identifiable angular positioning reference for determining the positional relationship of the mating holes. This step is intended to machine the reference hole in the outer sleeve male mold 2. When machining the second shaft, the hole will already exist, so this step does not need to be repeated.

[0050] The turbine wheel disc 11 is placed on the embedded female mold 3 through the spline, and the turbine wheel disc 11 is pressed and fixed by the pressure plate 10. The eye screw 7 is installed on the disc base 6 for lifting and moving the matching tooling. It is fixed on the machine tool to align the preset circumferential positioning reference on the disc base 6. The angular position of the matching through hole of the turbine wheel disc 11 is determined and then the matching through hole (second matching hole) is machined;

[0051] The outer sleeve male mold 2 is installed on the shaft 8 through the spline and fastened to the shaft end by the clamping bolt 1. Then the shaft is fixed on the machine tool to align the circumferential positioning reference hole (4-ΦD) on the outer sleeve male mold 2 to determine the angular position of the threaded hole for matching the shaft end and then process the threaded hole (first matching hole).

[0052] The shaft 8 and the turbine wheel 11 processed by the outer male mold 2 and the inner female mold 3 do not have a fixed pairing relationship with each other and can be paired arbitrarily.

[0053] The external splines of the inner female mold 3 have the same specifications as those of the shaft 8 and can mate with the splines of the turbine wheel 11 and the outer male mold 2. The spline teeth of the inner female mold 3 have a defined angular position relationship with the positioning reference, with a deviation within 0 to 0.25 degrees. This is consistent with the angular position relationship between the spline teeth of the outer male mold 2 and the positioning reference, with a position accuracy within 0 to 0.1. The angular position reference on the outer male mold 6 must be consistent with that on the outer male mold 2. The angular position reference can be distributed in any direction on the outer male mold 6. The positional relationship between the angular position reference and the splines of the outer male mold 2 is known and determined.

[0054] The specifications of the external splines of the outer male mold 2 are the same as those of the turbine impeller 11, and can be matched with the splines of the shaft 8 and the embedded female mold 3. Its spline teeth have a certain angular position relationship with the positioning reference, and the deviation is within 0~0.25°, which is consistent with the angular position relationship between the spline teeth of the embedded female mold 3 and the positioning reference, and the position accuracy is maintained within 0~0.1.

[0055] The principle of the scheme of the present invention is: utilizing the uniqueness of spline matching, using the embedded female mold 3 of the tooling to replace the turbine impeller 11 that matches the shaft 8, and the outer male mold 2 to replace the shaft 8 that matches the turbine impeller 11, and designing an identifiable angular positioning reference that can determine the position relationship of the matching holes on the outer male mold 2 and the disc base 6, and using the angular positioning reference to determine and process the matching holes, so that the shaft 8 processed using the embedded female mold 3 and the turbine impeller 11 processed using the outer male mold 2 can both be used in combination.

[0056] The present invention utilizes the uniqueness of spline fit, and the mating holes that need to be processed after the shaft and turbine disk are assembled together are completed in the single part processing process of the shaft or turbine disk by replacing the male and female molds. The corresponding tooling is designed with an identifiable angular positioning reference that can determine the positional relationship of the mating holes, ensuring that the circumferential relationship of the mating holes is correct after the turbine disk and the shaft are assembled. The method of the present invention uses the method of alternative fit to enable parts that require a unique matching relationship resulting from assembly and fitting processing to have universal and general mutual fit capabilities, that is, the same shaft can be matched with multiple turbine disks, and the same turbine disk can also be matched with multiple shafts. It has the advantages of high stability, good consistency, simple operation, and high safety. At the same time, it eliminates the assembly processing process of the mating holes, improves the assembly efficiency of the liquid rocket engine turbopump, and saves costs.

[0057] Example:

[0058] like Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 As shown, the liquid rocket engine turbopump shaft system matching hole tooling used in the present invention includes a tightening bolt 1, an outer sleeve male mold 2, an embedded female mold 3, a locating pin 4, a hexagonal bolt 5, a disc base 6, a lifting eye screw 7, a hexagonal shoulder nut 9, a pressure plate 10, a top block 12, a tapered end tightening screw 13, a push rod 14, a pull rod 15, a T-shaped block 16, etc.

[0059] The matching hole processing method of this embodiment includes:

[0060] (1) Figure 1 After the eye screw 7 is installed into the faceplate base 6, the faceplate base 6 is installed on the machine tool platform, the embedded female mold 3 is connected to the faceplate base through the hexagonal bolt 5, and a positioning pin hole with a diameter of Φ10 is processed.

[0061] (2) Grind the positioning pin 4. The positioning pin 4 has an interference fit with the faceplate base 6, with an interference of 0.01 to 0.02 mm. The positioning pin 4 has a clearance fit with the embedded female mold 3, with a clearance of 0.01 to 0.02 mm. Install the interference end of the ground positioning pin 4 into the faceplate base 6. The positioning pin fixes the position relationship between the embedded female mold 3 and the faceplate base 6. Figure 1 After the angular position is determined, the embedded female mold 3 is installed and the hexagonal bolt 5 is tightened.

[0062] (3) Install the outer male mold 2 on the inner female mold 3 and tighten it with the clamping bolt 1. First, process the angular positioning reference on the faceplate base 6, such as Figure 5 As shown, the angular positioning reference is used as the reference. Figure 1 In the assembly state shown, a 4-ΦD hole is machined on the end face of the outer sleeve male mold 2. The ΦD size is consistent with the matching hole size required by the drawings of the shaft 8 and the turbine impeller 11. This ensures that the angular position of the spline and the matching hole on the outer sleeve male mold 2 and the embedded female mold 3 are consistent.

[0063] (4) Figure 2 As shown, install the outer sleeve male mold 2 on the 8th shaft, use the clamping bolt 1 to tighten it, clamp the assembled shaft on the machine tool work platform, use the 4-ΦD hole processed in step (3) as a drilling jig, and process the shaft 8 matching hole according to the drawing requirements.

[0064] (5) Figure 3 As shown, install the turbine wheel 11 into the embedded female mold 3, assemble the pull rod 15 and T-shaped block 16 into a pull rod assembly and assemble it on the disc base 6, assemble the pressure plate 10, the top block 12, the cone-end set screw 13, the top rod 14, and the T-shaped block 16 into a top rod assembly and assemble it on the disc base 6, press Figure 3 As shown, the turbine wheel disc is compressed using a hexagonal shoulder nut 9, the angular positioning reference of step (3) is aligned, and a 4-ΦD hole is processed in the turbine wheel disc 11 in the same manner as step (3).

[0065] (6) Figure 4 As shown, after the shaft 8 processed in step (3) and the turbine wheel 11 processed in step (4) are assembled together, the end face 4-ΦD hole of the shaft 8 and the end face 4-ΦD of the turbine wheel 11 can be guaranteed to fit each other.

[0066] The present invention has been described in detail above with reference to specific embodiments and exemplary examples. However, these descriptions should not be construed as limiting the present invention. Those skilled in the art will appreciate that various equivalent substitutions, modifications, or improvements may be made to the technical solutions and implementations of the present invention without departing from the spirit and scope of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be determined by the appended claims.

[0067] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A tool for machining matching holes of a liquid rocket engine turbo pump shaft system, characterized in that: It comprises an outer male mold (2), an embedded female mold (3) and a faceplate base (6); The outer sleeve male mold (2) is a cylindrical structure with an open first end. The outer sleeve male mold (2) is provided with an internal spline, which is the same as the spline of the turbine wheel (11); The embedded female mold (3) is a columnar structure, and the second end of the embedded female mold (3) is provided with an external spline, which is the same as the spline of the shaft (8); The faceplate base (6) is fixedly mounted on the machine tool platform, the faceplate base (6) is used to connect to the first end of the embedded female mold (3), and an angular positioning reference is provided on the faceplate base (6); When the outer sleeve male mold (2) is sleeved on the outside of the second end of the embedded female mold (3), a through hole is machined on the second end of the outer sleeve male mold (2) based on an angular positioning reference; when the outer sleeve male mold (2) is sleeved on the outside of the shaft (8), a first matching hole is machined at a position on the shaft (8) corresponding to the through hole; When the turbine wheel disc (11) is sleeved on the outside of the second end of the embedded female mold (3), a second matching hole is machined on the turbine wheel disc (11) based on the angular positioning reference; The first matching hole and the second matching hole are used to realize the bolt connection between the turbine wheel (11) and the shaft (8).

2. A tool for machining matching holes of a liquid rocket engine turbo pump shaft according to claim 1, characterized in that: Also includes a clamping bolt (1); A bolt hole is provided at the center of the second end of the outer male mold (2), and the clamping bolt (1) passes through the bolt hole and is fixedly connected to the inner female mold (3) or the shaft (8), thereby achieving the clamping of the outer male mold (2) and the inner female mold (3) or the shaft (8).

3. A method for machining a matching hole of a liquid rocket engine turbo pump shaft system, characterized in that: The method is implemented by using a liquid rocket engine turbo pump shaft matching hole machining tool as claimed in claim 1 or 2, comprising: S1 installs the faceplate base (6) on the machine tool platform; The first end of the embedded female mold (3) is fixedly connected to the faceplate base (6); The outer male mold (2) is mounted on the outer side of the second end of the inner female mold (3), and the outer male mold (2) and the inner female mold (3) are pressed tightly; S2 sets an angular positioning reference on the faceplate base (6); S3 machining a through hole at the second end of the outer sleeve male mold (2) based on the angular positioning reference; S4: removing the outer male mold (2) from the inner female mold (3); sleeve the outer male mold (2) onto the outside of the shaft (8), press the outer male mold (2) and the shaft (8) tightly, and then process a first matching hole on the shaft (8) at a position corresponding to the through hole; S5: The turbine wheel disc (11) is placed on the outside of the second end of the embedded female mold (3), and after the turbine wheel disc (11) and the embedded female mold (3) are pressed tightly, a second matching hole is machined on the turbine wheel disc (11) based on an angular positioning reference.

4. A method for machining a matching hole in a liquid rocket engine turbo pump shaft according to claim 3, characterized in that: There are four first matching holes and four second matching holes.

5. The method for machining the matching hole of the liquid rocket engine turbo pump shaft system according to claim 3, characterized in that: In step S1, the method of fixing the first end of the embedded female mold (3) to the faceplate base (6) includes: The embedded female mold (3) is connected to the faceplate base (6) through a hexagonal bolt (5), and a first positioning pin hole and a second positioning pin hole are respectively processed on the embedded female mold (3) and the faceplate base (6); Grinding the positioning pin (4) so ​​that the positioning pin (4) and the first positioning pin hole have a clearance fit, and the positioning pin (4) and the second positioning pin hole have an interference fit; The clearance of clearance fit is 0.01~0.02mm, and the interference of interference fit is 0.01~0.02mm.

6. The method for machining the matching hole of the shaft system of a liquid rocket engine turbo pump according to claim 3, characterized in that: A bolt hole is provided at the center of the second end of the outer male mold (2), and the clamping bolt (1) passes through the bolt hole and is fixedly connected to the inner female mold (3) or the shaft (8), thereby achieving the clamping of the outer male mold (2) and the inner female mold (3) or the shaft (8).

7. The method for machining the matching hole of the shaft system of a liquid rocket engine turbo pump according to claim 3, characterized in that: In step S5, the turbine wheel disc (11) and the embedded female mold (3) are pressed together by using a pressure plate (10), a tie rod assembly and a push rod assembly; the tie rod assembly includes a tie rod (15) and a hexagonal shoulder nut (9), and the push rod assembly includes a push rod (14) and a push block (12); The pressure plate (10) is arranged above the turbine wheel (11); The lower end of the pull rod (15) is connected to the faceplate base (6) through a T-shaped block, and the upper end of the pull rod (15) passes upward through the pressure plate (10) and is pressed against the upper surface of the pressure plate (10) through a hexagonal shoulder nut (9); the lower end of the push rod (14) is connected to the faceplate base (6) through a T-shaped block, and the upper end of the push rod (14) is supported on the lower surface of the pressure plate (10) through a push block (12).

8. The method for machining the matching hole of the liquid rocket engine turbo pump shaft system according to claim 7, characterized in that: The distance between the top rod (14) and the axis of the turbine wheel disc (11) is greater than the distance between the pull rod (15) and the axis of the turbine wheel disc (11).

9. The method for machining a matching hole of a liquid rocket engine turbo pump shaft according to claim 7, characterized in that: Under the action of the pressing force and the supporting force exerted on the pressing plate (10), the pressing plate (10), the turbine wheel (11) and the faceplate base (6) are parallel.

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