Space droplet generator and spraying pointing precision control method thereof

Abstract

The invention relates to a space droplet generator and a spraying pointing precision control method thereof. The space droplet generator comprises a main shaft, a bearing seat, a shell, a bearing blocking seat, a spraying disc, a first deep groove ball bearing and a second deep groove ball bearing. The main shaft is arranged in the shell along the central axis of the shell; one end of the main shaft is used for being connected with a motor to achieve rotation, and a liquid working medium flow storage section is arranged at the other end of the main shaft and comprises a working medium channel and a liquid storage cavity communicated with the working medium channel. The middle part of the shell is provided with a side channel for a liquid working medium to pass through, and the working medium channel is communicated with the side channel; the spraying disc is arranged at the end of the liquid storage cavity, and the liquid working medium enters the liquid storage cavity through the side face channel and the working medium channel and then is sprayed out of the spraying disc. According to the processing precision of each part of the spatial droplet generator, the uncertainty of the spraying pointing precision of the spatial droplet generator is calculated, and the accurate control of the spraying pointing precision can be realized by controlling the processing precision.

Description

Technical Field

[0001] The present invention relates to a space droplet radiator in a spacecraft, and in particular to a space droplet generator and a method for controlling the spray pointing accuracy thereof. Background Art

[0002] In the space environment, spacecraft can only transfer heat through radiation. Space droplet radiators are a novel and highly efficient heat dissipation method. They primarily consist of a droplet generator, a droplet collector, a heat exchange system, and fluid piping. After the heat-absorbing liquid is ejected from the droplet generator, it forms a swarm of droplets that move according to a specific pattern. These droplets travel a certain distance in space, radiating heat before being recovered by the collector. Space droplet radiators offer advantages such as high scattering efficiency and a low-mass heat dissipation system. Their heat dissipation efficiency is primarily influenced by the droplet swarm's diameter, distribution characteristics, and motion patterns.

[0003] The spatial droplet generator is an important component of the spatial droplet radiator, which can achieve efficient generation and uniform distribution of droplet groups. The droplet group ejected from the spatial droplet generator has a tangential velocity, and the spatial distribution of the droplet group is in the shape of a truncated cone. The spacing between the droplets will gradually increase during the spatial movement, which has a strong heat exchange efficiency. However, due to the uncertainty of the injection accuracy of the spatial droplet generator itself, the difficulty of collecting the droplet group is increased. At the same time, with the support of the rotation speed of the spatial droplet generator, the uncertainty of the injection accuracy will be further increased. Therefore, in order to compensate for the above problems, the requirements for the injection accuracy of the spatial droplet generator are very high.

[0004] When the uncertainty of droplet ejection accuracy is large, the collection area of the droplet collector will far exceed the theoretical distribution area of the droplets, causing the volume and mass of the droplet radiation collector to increase dramatically. If the distribution area of the droplet group can be precisely controlled, the design of the droplet collector will be greatly simplified. Therefore, it is necessary to propose a spatial droplet generator with high ejection pointing accuracy. Summary of the Invention

[0005] The purpose of the present invention is to solve the technical problems of high uncertainty in the spraying accuracy of the existing spatial droplet generator and difficulty in collecting the sprayed droplet groups, and to provide a spatial droplet generator and a method for controlling the spraying pointing accuracy thereof.

[0006] The concept of the present invention is to calculate the uncertainty of the spray pointing accuracy of the spatial droplet generator based on the processing accuracy of each component of the spatial droplet generator, and to achieve precise control of the spray pointing accuracy by controlling the processing accuracy.

[0007] In order to achieve the above objectives and complete the above inventive concept, the technical solution adopted by the present invention is:

[0008] A spatial droplet generator is special in that it comprises a main shaft, a bearing seat, a housing, a bearing stopper, a spray disc, a first deep groove ball bearing, and a second deep groove ball bearing;

[0009] The main shaft is arranged in the shell along the central axis of the shell, and a wire channel is arranged along the axis thereof; one end of the main shaft is used to connect to the drive motor to realize rotation, and at the same time serves as the wire entry end of the excitation device, and the other end is provided with a liquid working medium flow storage section, and the liquid working medium flow storage section includes a liquid storage chamber and a working medium channel connected thereto at one end; the excitation device is arranged on the side wall of the liquid storage chamber near the side of the wire channel port, and a side channel for the passage of liquid working medium is provided in the middle of the shell, and the other end of the working medium channel is connected to one end of the side channel through an annular cavity arranged between the shell and the main shaft; the injection disc is arranged at the outer end of the liquid storage chamber, and a spray hole is arranged on it, and the spray hole is arranged in the axial direction or parallel to the axial direction; after the liquid working medium enters the liquid storage chamber through the side channel and the working medium channel, it is excited by the excitation device arranged in the liquid storage chamber and sprayed out from the spray hole of the injection disc;

[0010] The first deep groove ball bearing and the second deep groove ball bearing are respectively located at the two ends of the shell and are arranged between the main shaft and the shell; the first deep groove ball bearing is arranged close to one end of the main shaft and is fixed to the shell through a bearing seat; the second deep groove ball bearing is arranged close to the other end of the main shaft and is fixed to the shell through a bearing block seat.

[0011] Furthermore, it also includes a first dynamic seal and a second dynamic seal; the first dynamic seal and the second dynamic seal are both arranged between the main shaft and the housing, the first dynamic seal is located on the side of the annular cavity close to the second deep groove ball bearing, and the second dynamic seal is located on the side of the annular cavity close to the first deep groove ball bearing; the first dynamic seal and the second dynamic seal realize dynamic sealing between the main shaft and the housing.

[0012] Furthermore, an annular boss is provided on the outer side of the middle part of the main shaft, and the second dynamic seal is provided between the annular boss and the housing; a shaft sleeve is also provided on the main shaft, and the two ends of the shaft sleeve respectively abut against the inner ring of the first deep groove ball bearing and the step surface of the annular boss.

[0013] Furthermore, on the main shaft, between the annular boss and the other end, a first boss and a second boss are sequentially arranged from the inside to the outside, and the outer diameter of the second boss is larger than the outer diameter of the first boss; the first dynamic seal is arranged between the first boss and the housing, the second deep groove ball bearing is arranged between the second boss and the housing, and the liquid storage chamber is located in the second boss; an annular groove is provided on the inner side of the housing, and the annular cavity is formed between the inner side wall of the annular groove and the outer side wall of the end of the annular boss close to the other end of the main shaft, the outer side wall of the main shaft, and the outer side wall of the end of the second boss close to the annular boss; the other end port of the working fluid channel is located on the step surface of the second boss.

[0014] Furthermore, the main shaft and the spray disc are connected via threads; the spray holes are evenly arranged on the spray disc, the number of the spray holes is 20 to 50, and the diameter of the spray holes is 0.5 to 2 mm.

[0015] A method for controlling the spray pointing accuracy of a spatial droplet generator is provided, which is used for the above-mentioned spatial droplet generator and has the following features:

[0016] Step 1: Design a spatial droplet generator according to design requirements;

[0017] Step 2: Obtain the axis pointing accuracy θ1 of the spatial droplet generator main shaft, the disk-axis connection accuracy θ2 between the spray disk and the main shaft, and the nozzle pointing accuracy θ3, and obtain the total uncertainty of the spray pointing accuracy of the spatial droplet generator θ1+θ2+θ3;

[0018] Step 3: Define the maximum uncertainty of the design spray pointing accuracy of the spatial droplet generator as θ max , if θ1+θ2+θ3≤θ max , then the spatial droplet generator meets the design requirements and the spray pointing accuracy control of the spatial droplet generator is completed; if θ1+θ2+θ3>θ max , then return to step 1 and redesign the spatial droplet generator until θ1+θ2+θ3≤θ max .

[0019] Furthermore, in step 2, the specific method for obtaining the axis pointing accuracy θ1 of the main axis of the spatial droplet generator is:

[0020] Step 21.1: Obtain the maximum machining error δ of the spindle on the first and fifth mating surfaces. 17 , δ 18 And the processing coaxiality β1; wherein the first matching surface is the matching surface between the main shaft and the first deep groove ball bearing; the fifth matching surface is the matching surface between the main shaft and the second deep groove ball bearing;

[0021] Step 21.2: Obtain the maximum machining error δ of the bearing seat on the second and third mating surfaces.27 , δ 23 The machining coaxiality is β2; wherein the second mating surface is the mating surface between the bearing seat and the first deep groove ball bearing; the third mating surface is the mating surface between the bearing seat and the housing;

[0022] Step 21.3: Obtain the maximum machining error δ of the shell on the third and fourth mating surfaces 32 , δ 38 and processing coaxiality β3; wherein the fourth mating surface is the mating surface between the housing and the second deep groove ball bearing;

[0023] Step 21.4, obtain the maximum tolerance δ of the first deep groove ball bearing on the first fitting surface 72 and the radial runout σ1 on the second fitting surface; the maximum tolerance δ of the second deep groove ball bearing on the fourth fitting surface 83 and radial runout σ2 at the fifth mating surface;

[0024] In step 21.5, calculate the axis pointing accuracy θ1 according to the following formula:

[0025] θ1=arctan((|δ 17 |+|δ 18 |+|δ 27 |+|δ 23 |+|δ 32 |+|δ 38 |+|δ 72 |+|δ 83 |+β1+β2+β3+σ1+σ2) / L)

[0026] Wherein, L is the distance between the first deep groove ball bearing and the second deep groove ball bearing.

[0027] Furthermore, in step 2, the specific method for obtaining the disk-shaft connection accuracy θ2 between the injection disk and the main shaft is:

[0028] Obtain the perpendicularity α1 of the sixth mating surface of the main shaft and the injection disk relative to the fourth mating surface, and obtain the disk-shaft connection accuracy θ2 = α1.

[0029] Furthermore, in step 2, the specific method for obtaining the nozzle pointing accuracy θ3 is:

[0030] Step 23.1, obtaining the perpendicularity α2 between the axis of the spray hole on the spray disk and its outer surface, and obtaining the angular deviation of the axis of the spray hole relative to the outer surface of the spray disk as α2;

[0031] Step 23.2, obtaining the parallelism deviation u1 between the inner and outer surfaces of the spray disc, and obtaining the angular deviation u1 between the inner and outer surfaces of the spray disc;

[0032] In step 23.3, calculate the nozzle pointing accuracy θ3 according to the following formula:

[0033] θ3=α2+u1.

[0034] Further,

[0035] In step 3, if θ1+θ2+θ3>θ max , then return to step 1, and establish the injection precision control equation, and recalculate and determine the machining precision of the main shaft, bearing seat, shell and injection disk of the spatial droplet generator;

[0036] The injection accuracy control equation is:

[0037] min f=k1|δ 17 |+k1|δ 18 |+k1|δ 27 |+k1|δ 23 |+k1|δ 32 |+k1|δ 38 |+K2|β1|+k2|β2|+K2|β3|++K3α1+k3α2+k4u1

[0038] Among them, k1 is the difficulty of machining the circular surface of the main shaft, bearing seat and housing; k2 is the difficulty of the coaxiality of the main shaft, bearing seat and housing; k3 is the difficulty of the verticality of the injection disk; k4 is the difficulty of the parallelism of the injection hole of the injection disk.

[0039] Compared with the prior art, the present invention has the following beneficial technical effects:

[0040] 1. The spatial droplet generator and the method for controlling the spray pointing accuracy thereof of the present invention can calculate the maximum uncertainty of the spray pointing accuracy of the spatial droplet generator based on the assembly structure and processing error of the spatial droplet generator, which is of great significance to the use of the spatial droplet generator.

[0041] 2. The spatial droplet generator and the method for controlling the spray pointing accuracy thereof of the present invention can adjust the processing accuracy of each component according to the processing technology level during the design stage of the spatial droplet generator, thereby realizing precise control of the spray pointing accuracy of the spatial droplet generator, and adopting the simplest processing technology to ensure the optimal spray pointing accuracy, thereby making up for the shortcoming that the spray pointing accuracy is difficult to control during the design process of the traditional spatial droplet generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic structural diagram of an embodiment of a spatial droplet generator of the present invention;

[0043] Figure 2 This is a schematic diagram of the axis pointing deviation of an embodiment of the spatial droplet generator of the present invention;

[0044] The following are the descriptions of the reference numerals:

[0045] 1-main shaft, 2-bearing seat, 3-housing, 4-bearing seat, 5-injection disc, 6-sleeve, 7-first deep groove ball bearing, 8-second deep groove ball bearing, 9-first dynamic seal, 10-second dynamic seal, 11-first mating surface, 12-second mating surface, 13-third mating surface, 14-fourth mating surface, 15-fifth mating surface, 16-sixth mating surface, 111-working fluid channel, 112-liquid storage chamber, 113-side channel. DETAILED DESCRIPTION

[0046] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0047] like Figure 1 As shown, the present invention provides a method for calculating and controlling the spray pointing accuracy of a spatial droplet generator, which mainly includes: a main shaft 1, a bearing seat 2, a housing 3, a bearing stop 4, a spray disc 5, a sleeve 6, a first deep groove ball bearing 7, a second deep groove ball bearing 8, a first dynamic seal 9, and a second dynamic seal 10. The main shaft 1 is fixed to the housing 3 using the first deep groove ball bearing 7 and the second deep groove ball bearing 8. The left side of the main shaft 1 is connected to the motor to realize the rotation of the shaft 1. The distance between the first deep groove ball bearing 7 and the second deep groove ball bearing 8 is L. The liquid working medium enters from the side channel of the housing 3, passes through the main shaft 1, and is excited by the excitation device and sprayed out from the spray disc 5. 20 to 50 spray holes are evenly arranged on the spray disc 5, with a diameter of 0.5 to 2 mm. The first dynamic seal 9 and the second dynamic seal 10 can realize the dynamic seal between the main shaft 1 and the housing 3 to ensure that the liquid working medium does not leak.

[0048] The spray pointing accuracy of the spatial droplet generator is primarily composed of the axis pointing accuracy θ1, the disk-shaft connection accuracy θ2, and the nozzle orifice pointing accuracy θ3. The axis pointing accuracy θ1 is controlled by the fit accuracy of the first mating surface 11 between the shaft 1 and the first deep groove ball bearing 7, the second mating surface 12 between the bearing seat 2 and the first deep groove ball bearing 7, the third mating surface 13 between the bearing seat 2 and the housing 3, the fourth mating surface 14 between the housing 3 and the second deep groove ball bearing 8, and the fifth mating surface 15 between the main shaft 1 and the second deep groove ball bearing 8. The disk-shaft connection accuracy θ2 is controlled by the fit accuracy of the sixth mating surface 16 between the main shaft 1 and the spray disk 5. The nozzle orifice pointing accuracy θ3 is controlled by the machining accuracy of the spray disk 5 and the nozzle orifice drilling accuracy. The total uncertainty of the spray pointing accuracy is θ1 + θ2 + θ3.

[0049] The calculation method of axis pointing accuracy θ is as follows: the maximum machining error of the spindle 1 on the first mating surface 11 and the fifth mating surface 15 is δ 17 and δ18 , the machining coaxiality is β1; the maximum machining error of the bearing seat 2 on the second mating surface 12 and the third mating surface 13 is δ 27 and δ 23 , the processing coaxiality is β2; the maximum processing δ of the shell 3 at the third mating surface 13 and the fourth mating surface 14 32 and δ 38 , the machining coaxiality is β3; the maximum tolerance sum of the first deep groove ball bearing 7 on the first mating surface 11 and the second mating surface 12 is δ 72 , the radial runout is σ1; the maximum tolerance sum of the second deep groove ball bearing 8 on the fourth fitting surface 14 and the fifth fitting surface 15 is δ 83 , the radial runout is σ2.

[0050] like Figure 2 As shown, the pointing accuracy of the axis θ1 is,

[0051] θ1=arctan((|δ 17 |+|δ 18 |+|δ 27 |+|δ 23 |+|δ 32 |+|δ 38 |+|δ 72 |+|δ 83 |+β1+β2+σ1+σ2) / L).

[0052] The calculation method of the disk-shaft connection accuracy θ2 is: the main shaft 1 and the injection disk 5 are connected by threads, and the sixth mating surface 16 is used for positioning. The verticality of the shaft 1 at the sixth mating surface 16 relative to the fourth mating surface 14 is α1, the installation error between the injection disk 5 and the main shaft 1 is α1, and the disk-shaft connection accuracy θ2 = α1.

[0053] The calculation method of the nozzle pointing accuracy θ3 is: the perpendicularity between the nozzle axis on the nozzle disk 5 and its outer surface is α2, then the angular deviation of the nozzle axis relative to the outer surface of the nozzle disk is α2; the parallelism deviation of the inner and outer surfaces of the nozzle disk 5 is u1, then the angular deviation of the inner and outer surfaces of the nozzle disk is u1, then the nozzle pointing accuracy θ3 = α2 + u1.

[0054] The actual spray pointing accuracy of the spatial droplet generator is affected by the processing technology, which makes the spray accuracy control more difficult. In order to achieve precise control of the spray accuracy, it is necessary to determine the processing accuracy of each component according to the processing technology level, so as to achieve precise control of the spray pointing accuracy. When the design requires the spray pointing accuracy of the spatial droplet generator to be no greater than θ max The least squares method is used to solve the jet pointing accuracy control equation, thereby obtaining the machining accuracy of the spindle 1, bearing seat 2, housing 3, and jet disc 5. The first deep groove ball bearing 7 and the second deep groove ball bearing 8 are finished parts, and their accuracy is determined by themselves.

[0055] The control equation of the injection pointing accuracy can be described as:

[0056] min f=k1|δ 17 |+k1|δ 18 |+k1|δ 27 |+k1|δ 23 |+k1|δ 32 |+k1|δ 38 |+K2|β1|+K2|β2|+K2|β3|++k3α1+k3α2+k4u1

[0057] To meet the design and assembly requirements, the machining error should meet the following constraints:

[0058]

[0059] Where k1 is the difficulty level of machining the circular surfaces of spindle 1, bearing seat 2, and housing 3; k2 is the difficulty level of achieving coaxiality among spindle 1, bearing seat 2, and housing 3; k3 is the difficulty level of achieving perpendicularity in jet disk 5; and k4 is the difficulty level of achieving parallelism in the jet disk 5's nozzles. The range of these values can be determined based on the machining process. When k1 = 1, 0.01 ≤ |δ| < 0.02; when k1 = 2, 0.001 ≤ |δ| < 0.01; and when k1 = 3, |δ| < 0.001. When k2 = 1, 0.005 ≤ β < 0.01; when k2 = 2, 0.001 ≤ β < 0.005; and when k2 = 3, β < 0.001. When k3=1, 0.005≤α<0.01; when k3=2, 0.001≤α<0.005; when k3=3, α<0.001. When k4=1, 0.005≤u<0.01; when k4=2, 0.001≤u<0.005; when k4=3, u<0.001.

[0060] A method for controlling the spray pointing accuracy of a spatial droplet generator is mainly based on the processing technology level. By controlling the processing accuracy of each component, mainly including the maximum processing error, verticality, parallelism and coaxiality, the precise control of the spray pointing accuracy is achieved. The specific control steps of the spray pointing accuracy are as follows:

[0061] Step 1: Design a spatial droplet generator according to design requirements;

[0062] Step 2: Obtain the axis pointing accuracy θ1 of the main shaft 1 of the spatial droplet generator, the disk axis connection accuracy θ2 between the injection disk 5 and the main shaft 1, and the nozzle pointing accuracy θ3, and obtain the total uncertainty θ1+θ2+θ3 of the injection pointing accuracy of the spatial droplet generator;

[0063] Step 3: Define the maximum uncertainty of the design spray pointing accuracy of the spatial droplet generator as θ max , if θ1+θ2+θ3≤θ max , the spatial droplet generator meets the design requirements; if θ1+θ2+θ3>θ max , solve the machining accuracy calculation equation group to determine the machining accuracy of the main shaft 1, bearing seat 2, shell 3 and injection disk 5 of the spatial droplet generator.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A spatial droplet generator, characterized in that: It comprises a main shaft (1), a bearing seat (2), a housing (3), a bearing stop seat (4), a jet disc (5), a first deep groove ball bearing (7), and a second deep groove ball bearing (8); The main shaft (1) is arranged in the shell (3) along the central axis of the shell (3); one end of the main shaft (1) is used to connect to the drive motor to realize rotation, and the other end thereof is provided with a liquid working medium flow storage section, and the liquid working medium flow storage section includes a liquid storage chamber (112) and a working medium channel (111) connected to the liquid storage chamber at one end; a side channel (113) for the liquid working medium to pass through is provided in the middle of the shell (3), and the other end of the working medium channel (111) is connected to one end of the side channel (113) through an annular cavity arranged between the shell (3) and the main shaft (1); the injection disc (5) is arranged at the outer end of the liquid storage chamber (112), and is provided with spray holes arranged in the axial direction or in a direction parallel to the axial direction; after the liquid working medium enters the liquid storage chamber (112) through the side channel (113) and the working medium channel (111), it is excited by an excitation device arranged in the liquid storage chamber (112) and ejected from the spray holes of the injection disc (5); The first deep groove ball bearing (7) and the second deep groove ball bearing (8) are respectively located at two ends inside the housing (1) and are arranged between the main shaft (1) and the housing (3); the first deep groove ball bearing (7) is arranged close to one end of the main shaft (1) and is fixed to the housing (3) via a bearing seat (2); the second deep groove ball bearing (8) is arranged close to the other end of the main shaft (1) and is fixed to the housing (3) via a bearing stop seat (4).

2. The spatial droplet generator according to claim 1, characterized in that: The invention also includes a first dynamic seal (9) and a second dynamic seal (10); the first dynamic seal (9) and the second dynamic seal (10) are both arranged between the main shaft (1) and the housing (3); the first dynamic seal (9) is located on the side of the annular cavity close to the second deep groove ball bearing (8), and the second dynamic seal (10) is located on the side of the annular cavity close to the first deep groove ball bearing (7); the first dynamic seal (9) and the second dynamic seal (10) realize dynamic sealing between the main shaft (1) and the housing (3).

3. The spatial droplet generator according to claim 2, characterized in that: An annular boss is provided on the outer side of the middle portion of the main shaft (1), and the second dynamic seal (10) is provided between the annular boss and the housing (3); a shaft sleeve (6) is also sleeved on the main shaft (1), and the two ends of the shaft sleeve (6) respectively abut against the inner ring of the first deep groove ball bearing (7) and the step surface of the annular boss.

4. The spatial droplet generator according to claim 3, characterized in that: On the main shaft (1), between the annular boss and the other end, a first boss and a second boss are sequentially arranged from the inside to the outside, and the outer diameter of the second boss is larger than the outer diameter of the first boss; the first dynamic seal (9) is arranged between the first boss and the housing (3), the second deep groove ball bearing (8) is arranged between the second boss and the housing (3), and the liquid storage cavity (112) is located in the second boss; an annular groove is arranged on the inner side of the housing (3), and the annular cavity is formed between the inner side wall of the annular groove and the outer side wall of the end of the annular boss close to the other end of the main shaft (1), the outer side wall of the main shaft (1), and the outer side wall of the end of the second boss close to the annular boss; the other end port of the working fluid channel (111) is located on the step surface of the second boss.

5. The spatial droplet generator according to claim 3, characterized in that: The main shaft (1) and the spray disc (5) are connected via threads; the spray holes are evenly arranged on the spray disc (5), the number of the spray holes is 20 to 50, and the diameter of the spray holes is 0.5 to 2 mm.

6. A method for controlling the spray pointing accuracy of a spatial droplet generator, used for the spatial droplet generator according to claim 1, characterized in that: The following steps are involved: Step 1: Design a spatial droplet generator according to design requirements; Step 2: Obtain the axis pointing accuracy θ1 of the main shaft (1) of the spatial droplet generator, the disk axis connection accuracy θ2 between the injection disk (5) and the main shaft (1), and the nozzle pointing accuracy θ3, and obtain the total uncertainty of the injection pointing accuracy of the spatial droplet generator θ1+θ2+θ 3； Step 3: Define the maximum uncertainty of the design spray pointing accuracy of the spatial droplet generator as θ max , if θ1+θ2+θ3≤θ max , then the spatial droplet generator meets the design requirements and the spray pointing accuracy control of the spatial droplet generator is completed; if θ1+θ2+θ3>θ max , then return to step 1 and redesign the spatial droplet generator until θ1+θ2+θ3≤θ max .

7. The method for controlling the spray pointing accuracy of a spatial droplet generator according to claim 6, characterized in that: In step 2, the specific method for obtaining the axis pointing accuracy θ1 of the main axis (1) of the spatial droplet generator is: Step 21.1, obtain the maximum machining error δ of the spindle (1) on the first mating surface (11) and the fifth mating surface (15) 17 , δ 18 and processing coaxiality β1; wherein the first mating surface (11) is the mating surface between the main shaft (1) and the first deep groove ball bearing (7); the fifth mating surface (15) is the mating surface between the main shaft (1) and the second deep groove ball bearing (8); Step 21.2, obtain the maximum machining error δ of the bearing seat (2) on the second mating surface (12) and the third mating surface (13) 27 , δ 23 and the processing coaxiality is β2; wherein the second mating surface (12) is the mating surface between the bearing seat (2) and the first deep groove ball bearing (7); and the third mating surface (13) is the mating surface between the bearing seat (2) and the housing (3); Step 21.3, obtain the maximum machining error δ of the shell (3) at the third mating surface (13) and the fourth mating surface (14) 32 , δ 38 and processing coaxiality β3; wherein the fourth matching surface (14) is the matching surface between the housing (3) and the second deep groove ball bearing (8); Step 21.4, obtaining the maximum tolerance δ of the first deep groove ball bearing (7) on the first fitting surface (11) 72 and the radial runout σ1 at the second fitting surface (12); the maximum tolerance δ of the second deep groove ball bearing (8) at the fourth fitting surface (14) 83 and radial runout σ2 at the fifth mating surface (15); In step 21.5, calculate the axis pointing accuracy θ1 according to the following formula: θ1=arctan((|δ 17 |+|d 18 |+|d 27 |+|d 23 |+|d 32 |+|d 38 |+|d 72 |+|d 83 |+β1+β2+β3+σ1+σ2) / L) Wherein, L is the distance between the first deep groove ball bearing (7) and the second deep groove ball bearing (8).

8. The method for controlling the spray pointing accuracy of a spatial droplet generator according to claim 7, characterized in that: In step 2, the specific method for obtaining the disk-shaft connection accuracy θ2 between the injection disk (5) and the main shaft (1) is: The perpendicularity α1 of the sixth mating surface (16) of the main shaft (1) and the injection disc (5) relative to the fourth mating surface (14) is obtained, and the disc-shaft connection accuracy θ2=α1 is obtained.

9. The method for controlling the spray pointing accuracy of a spatial droplet generator according to claim 8, characterized in that: In step 2, the specific method for obtaining the nozzle pointing accuracy θ3 is: Step 23.1, obtaining the perpendicularity α2 between the axis of the spray hole on the spray disk (5) and its outer surface, and obtaining the angular deviation of the axis of the spray hole relative to the outer surface of the spray disk (5) as α2; Step 23.2, obtaining the parallelism deviation u1 of the inner and outer surfaces of the injection disk (5), and obtaining the angular deviation u1 of the inner and outer surfaces of the injection disk (5); Step 23.3, calculate the nozzle pointing accuracy θ3 according to the following formula: θ3 = α2 + u1.

10. The method for controlling the spraying direction accuracy of a spatial droplet generator according to claim 9, characterized in that: In step 3, if θ1+θ2+θ3>θ max , then return to step 1, and establish the injection precision control equation, and recalculate and determine the machining precision of the main shaft (1), bearing seat (2), shell (3) and injection disk (5) of the spatial droplet generator; The injection accuracy control equation is: minf=k1|δ 17 |+k1|d 18 |+k1|d 27 |+k1|d 23 |+k1|d 32 |+k1|d 38 |+K2|β1|+K2|β2|+K2|β3|+k3α1+k3α2+k4u1 Among them, k1 is the difficulty of machining the circular surface of the main shaft (1), the bearing seat (2) and the housing (3); k2 is the difficulty of the coaxiality of the main shaft (1), the bearing seat (2) and the housing (3); k3 is the difficulty of the verticality of the injection disc (5); and k4 is the difficulty of the parallelism of the injection holes of the injection disc (5).

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