Sealing driving mechanism of lunar soil water molecule analyzer and assembly method of sealing driving mechanism

Abstract

The invention discloses a lunar soil water molecule analyzer sealing driving mechanism and an assembling method thereof. The lunar soil water molecule analyzer sealing driving mechanism comprises a trapezoidal screw rod, a worm gear case, a bearing outer pressing ring, a first bearing, a first bearing pad, a second bearing pad, a bearing seat, a worm, a worm gear, a worm gear fixing ring, a third bearing, a bearing inner pressing ring, a second bearing pad and a third bearing pad. During assembly, the requirement for pretightening force of the first bearing and the second bearing pad is met by grinding the first bearing pad and the third bearing pad, and the worm gear and worm meshing position is adjusted by repairing the second bearing pad. The assembling method is simple and effective, the difficulty of assembling the solid lubrication bearing is reduced, and meanwhile the problem of grinding grease pollution of the worm gear and the worm is solved.

Description

Technical Field

[0001] The present invention relates to the field of lunar soil water ice content detection, and in particular to a sealing drive mechanism of a lunar soil water molecule analyzer and an assembly method thereof. Background Art

[0002] The lunar soil water molecule analyzer is used to detect water ice in the lunar soil and the hydrogen and oxygen isotopes contained in the water ice, which is of great significance to scientific research and the development and utilization of lunar resources. When working on orbit, the lunar soil water molecule analyzer needs to use a sealed drive mechanism to send the lunar soil water ice sample held by the sample holder to the heating furnace for heating and analysis. The sealed drive mechanism belongs to the on-board active mechanism, and the operating temperature range is -55℃~+35℃. In order to ensure the reliability of the active mechanism on orbit, the bearings and trapezoidal screws are designed to adopt the MoS2-4 type multi-layer composite film lubrication method; this lubrication method can adapt well to the wide temperature range environment, but it is sensitive to humidity and excess. In addition, a large amount of grinding paste needs to be applied to the key transmission parts when the worm gear is running in order to obtain a good transmission effect; in order to prevent grinding paste contamination, the shaft system is installed with process bearings and process screws for testing when the worm gear is running in. After running in this way, due to the different sizes and preloads of the inner and outer rings of the process bearings and the formal bearings, the meshing position of the worm gear will change, resulting in unsmooth transmission. Summary of the invention

[0003] The present invention provides a sealing drive mechanism for a lunar soil water molecule analyzer and an assembly method thereof to solve the problems in the above-mentioned background technology.

[0004] To solve the above problems, the present invention provides the following technical solutions:

[0005] A sealing drive mechanism of a lunar soil water molecule analyzer, comprising a trapezoidal screw, a worm gear box, a bearing outer pressure ring, a first bearing, a first bearing pad, a second bearing pad, a bearing seat, a worm, a worm gear, a worm gear fixing ring, a third bearing, a bearing inner pressure ring, a second bearing pad and a third bearing pad;

[0006] The trapezoidal lead screw is dynamically fitted with a first bearing, a second bearing pad and a third bearing; the inner ring of the first bearing is fastened to the trapezoidal lead screw via the third bearing pad, the inner ring of the second bearing pad, the second bearing pad, the worm gear fixing ring, the third bearing inner ring and the bearing inner pressure ring; one end of the outer ring of the first bearing is limited by the first bearing pad and the outer ring of the second bearing pad, and the other end is statically fitted on the bearing seat fixed on the worm gear box via the bearing outer pressure ring; one end of the worm gear is dynamically connected to the trapezoidal lead screw via the worm gear fixing ring, and the other end is meshed with the staggered shaft of the worm.

[0007] As a further solution of the present invention: a MoS2-4 type multilayer composite film is plated on the surface of the trapezoidal lead screw.

[0008] As a further solution of the present invention: the first bearing and the second bearing pad are 71800AC angular contact ball bearings, the bearings are lubricated by MoS2-4 type multi-layer composite film, and are used in back-to-back pairs; the protrusions of the preload force of 50N are 0.092mm and 0.102mm respectively, and the starting friction forces are 1.45mN·m and 1.41mN·m respectively.

[0009] As a further solution of the present invention: the third bearing is a 61900 deep groove ball bearing, the bearing adopts a lubrication method of plating MoS2-4 type multi-layer composite film, and the starting friction force is 1.3mN·m when the axial force is 50N.

[0010] As a further solution of the present invention: the worm and the worm wheel are lubricated with 601-EF low-temperature grease.

[0011] Another aspect of the present invention discloses a method for assembling a sealing drive mechanism of a lunar soil water molecule analyzer as described in any one of the above, comprising the following steps:

[0012] S1. After the worm gear of the sealed drive mechanism is run-in with the process bearing, measure the distance h1 between the left end face of the process third bearing and the left end face of the worm gear box and the inner ring thickness h2 of the process third bearing, and calculate the distance H1=h1+h2 between the left end face of the worm gear fixing ring installed under the process bearing and the left end face of the worm gear box;

[0013] S2. Grind the first bearing pad and the third bearing pad according to the protrusion of the first bearing and the second bearing pad under the preload of 50N to ensure that the parallelism of both end surfaces of the first bearing pad and the third bearing pad is better than 0.003mm, and the difference between the height L1 of the first bearing pad and the height L3 of the third bearing pad is equal to the sum of the protrusions of the two bearings, that is, L1-L3=0.092mm+0.102mm=0.194mm;

[0014] S3. Install the first bearing, the first bearing pad, the third bearing pad, the second bearing pad, the second bearing pad, the worm gear fixing ring, the third bearing and lock the inner pressure ring of the bearing, test the starting friction torque and rotation runout of the trapezoidal screw, and judge the bearing preload condition and installation quality according to the starting friction force and runout value;

[0015] S4. Measure the distance h3 between the left end face of the third bearing and the left end face of the worm gear box and the thickness h4 of the inner ring of the third bearing, and calculate that the distance between the left end face of the worm gear fixing ring installed under the formal bearing and the left end face of the worm gear box is H2=h3+h4;

[0016] S5. Calculate the difference △=H1-H2, grind off the height L2 of the second bearing pad by the △ value and ensure that the parallelism of the two end surfaces of the second bearing pad is better than 0.003mm.

[0017] The beneficial effects of the present invention are:

[0018] (1) The combination of grease and MoS2-4 solid lubrication ensures the high reliability of the sealing drive mechanism over a wide temperature range;

[0019] (2) The preload requirement of the first and second bearing pads can be achieved by grinding the first and third bearing pads, and the meshing position of the worm gear can be adjusted by repairing the second bearing pad, which greatly reduces the assembly difficulty caused by bearing replacement and solves the problem of worm gear grinding grease contaminating the bearing and trapezoidal lead screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the basic structure of the sealing drive mechanism of the lunar soil water molecule analyzer of the present invention.

[0021] Figure 2 Schematic diagram for calculating the distance H1 between the left end face of the worm gear fixing ring and the left end face of the worm gear box when installing the process bearing for the sealed drive mechanism.

[0022] Figure 3 It is a schematic diagram of the structure of the first bearing pad and the third bearing pad.

[0023] Figure 4 Schematic diagram for calculating the distance H2 between the left end face of the worm gear fixing ring and the left end face of the worm gear box when installing the formal bearing for the sealed drive mechanism.

[0024] Figure 5 Schematic diagram of the seal drive mechanism bearing preload condition and installation quality test.

[0025] Figure 6 It is a schematic diagram of the structure of the second bearing pad.

[0026] Among them, 1 is a trapezoidal screw, 2 is a worm gear box, 3 is a bearing outer pressure ring, 4 is a first bearing, 5 is a first bearing pad, 6 is a second bearing, 7 is a bearing seat, 8 is a worm, 9 is a worm gear, 10 is a worm gear fixing ring, 11 is a third bearing, 12 is a bearing inner pressure ring, 13 is a second bearing pad, and 14 is a third bearing pad. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. However, the following embodiments are limited to explaining the present invention, and the protection scope of the present invention should include the entire contents of the claims, and through the description of the following embodiments, those skilled in the art can fully implement the entire contents of the claims of the present invention.

[0028] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0029] Example

[0030] See also Figure 1 , a sealing drive mechanism of a lunar soil water molecule analyzer and an assembly method thereof, comprising a trapezoidal screw 1, a worm gear box 2, a bearing outer pressure ring 3, a first bearing 4, a first bearing pad 5, a second bearing 6, a bearing seat 7, a worm 8, a worm gear 9, a worm gear fixing ring 10, a third bearing 11, a bearing inner pressure ring 12, a second bearing pad 13 and a third bearing pad 14;

[0031] The trapezoidal lead screw 1 is dynamically fitted with a first bearing 4, a second bearing 6 and a third bearing 11. The inner ring of the first bearing 4 is fastened to the trapezoidal lead screw 1 via a third bearing pad 14, an inner ring of the second bearing 6, a second bearing pad 13, a worm wheel fixing ring, an inner ring of the third bearing 11 and a bearing inner pressure ring 12; one end of the outer ring of the first bearing 4 is limited by the first bearing pad 5 and the outer ring of the second bearing 6, and the other end thereof is statically fitted on a bearing seat 7 fixed on the worm gear box 2 via a bearing outer pressure ring 3; one end of the worm wheel 9 is dynamically connected to the trapezoidal lead screw 1 via a worm wheel fixing ring 10, and the other end thereof is meshed with the staggered axis of the worm 8;

[0032] As a further solution of the present invention: the surface of the trapezoidal lead screw 1 is coated with a MoS2-4 type multilayer composite film.

[0033] As a further solution of the present invention: the first bearing 4 and the second bearing 6 are 71800AC angular contact ball bearings, which are lubricated by MoS2-4 type multi-layer composite film and are used in back-to-back pairs; the protrusions of the preload force of 50N are 0.092mm and 0.102mm respectively, and the starting friction forces are 1.45mN·m and 1.41mN·m respectively.

[0034] As a further solution of the present invention: the third bearing 11 is a 61900 deep groove ball bearing, the bearing adopts a lubrication method of MoS2-4 type multi-layer composite film plating, and the starting friction force is 1.3mN·m when the axial force is 50N.

[0035] As a further solution of the present invention: the worm 8 and the worm wheel 9 are lubricated with 601-EF low-temperature grease.

[0036] See also Figure 2 , measure the distance h1 between the left end face of the third bearing 11 and the left end face of the worm gear box 2 and the inner ring thickness h2 of the third bearing 11, h1=2.218mm, h2=5.990mm, calculate the distance between the left end face of the worm gear fixing ring 10 under the installation process bearing and the left end face of the worm gear box 2 H1=h1+h2=2.218mm+5.990mm=8.208mm.

[0037] See also Figure 3After grinding the first bearing pad 5 and the third bearing pad 14, the thickness of the first bearing pad 5 was tested to be L1=1.192mm, and the parallelism of the two end surfaces K1 and K2 of the first bearing pad 5 was 0.0013mm; the thickness of the third bearing pad 14 was tested to be L3=0.998mm, and the parallelism of the two end surfaces K3 and K4 of the third bearing pad 14 was 0.0011mm, which met the preload requirement.

[0038] See also Figure 4 , measure the distance h3 between the left end face of the third bearing 11 and the left end face of the worm gear box 2 and the inner ring thickness h4 of the third bearing 11, h3=2.014mm, h4=5.992mm, calculate the distance H2=h3+h4=2.014mm+5.992mm=8.006mm between the left end face of the worm gear fixing ring 10 and the left end face of the worm gear box 2 installed under the formal bearing.

[0039] See also Figure 5 The radial runout at D1 of the trapezoidal screw 1, the end face runout at D2 and the starting friction torque of the trapezoidal screw were measured. The measured radial runout of D1 was 0.012mm, which met the requirement of no more than 0.02mm; the end face runout at D2 was 0.006mm, which met the requirement of no more than 0.01mm; the starting friction torque of the trapezoidal screw was 4.2mN·m, which was within the range of (4.0~5.0)mN·m, indicating that the bearing preload was successfully applied.

[0040] See also Figure 6 According to △=H1-H2=8.208mm-8.006mm=0.202mm, the thickness L2 of the second bearing pad 13 is ground from 1.18mm to 0.978mm, and the parallelism of the two end surfaces K5 and K6 of the second bearing pad 13 is 0.0009mm, which meets the requirements.

[0041] The sealing drive mechanism manufactured and assembled according to the present invention can adapt to the temperature condition of -55°C ~ +35°C, and all performance indicators tested meet the requirements, and have passed the assessment of environmental tests such as mechanical vibration test, thermal vacuum test and other environmental tests given by the satellite as a whole.

[0042] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A sealing drive mechanism for a lunar soil water molecule analyzer, characterized in that: It comprises a trapezoidal lead screw (1), a worm gear box (2), a bearing outer pressure ring (3), a first bearing (4), a first bearing pad (5), a second bearing pad (6), a bearing seat (7), a worm (8), a worm gear (9), a worm gear fixing ring (10), a third bearing (11), a bearing inner pressure ring (12), a second bearing pad (13) and a third bearing pad (14); The trapezoidal lead screw (1) is movably mounted with a first bearing (4), a second bearing pad (6) and a third bearing (11); the inner ring of the first bearing (4) is fastened to the trapezoidal lead screw (1) via the third bearing pad (14), the inner ring of the second bearing pad (6), the second bearing pad (13), the worm wheel fixing ring (10), the inner ring of the third bearing (11) and the bearing inner pressure ring (12); one end of the outer ring of the first bearing (4) is limited by the first bearing pad (5) and the outer ring of the second bearing pad (6), and the other end is statically mounted on a bearing seat (7) fixed on the worm gear box (2) via the bearing outer pressure ring (3); one end of the worm wheel (9) is movably connected to the trapezoidal lead screw via the worm wheel fixing ring (10), and the other end is meshed with the staggered axis of the worm (8).

2. The sealing drive mechanism of the lunar soil water molecule analyzer according to claim 1, characterized in that: The surface of the trapezoidal lead screw (1) is coated with a MoS2-4 type multilayer composite film.

3. The sealing drive mechanism of the lunar soil water molecule analyzer according to claim 1, characterized in that: The first bearing (4) and the second bearing pad (6) are 71800AC angular contact ball bearings, which are lubricated by coating a MoS2-4 type multilayer composite film and are used in a back-to-back pair; the protrusions at a preload force of 50N are 0.092mm and 0.102mm respectively, and the starting friction forces are 1.45mN·m and 1.41mN·m respectively.

4. The sealing drive mechanism of the lunar soil water molecule analyzer according to claim 1, characterized in that: The third bearing (11) is a 61900 deep groove ball bearing, and the bearing is lubricated by a MoS2-4 type multilayer composite film, and the starting friction force is 1.3 mN·m when the axial force is 50N.

5. The sealing drive mechanism of the lunar soil water molecule analyzer according to claim 1, characterized in that: The worm (8) and the worm wheel (9) are lubricated with 601-EF low-temperature grease.

6. The method for assembling the sealing drive mechanism of the lunar soil water molecule analyzer according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. After the worm gear of the sealed drive mechanism is run-in with the process bearing, measure the distance h1 between the left end face of the process third bearing and the left end face of the worm gear box and the inner ring thickness h2 of the process third bearing, and calculate the distance H1=h1+h2 between the left end face of the worm gear fixing ring installed under the process bearing and the left end face of the worm gear box; S2. Grind the first bearing pad and the third bearing pad according to the protrusion of the first bearing and the second bearing pad under the preload of 50N to ensure that the parallelism of both end surfaces of the first bearing pad and the third bearing pad is better than 0.003mm, and the difference between the height L1 of the first bearing pad and the height L3 of the third bearing pad is equal to the sum of the protrusions of the two bearings, that is, L1-L3=0.092mm+0.102mm=0.194mm; S3. Install the first bearing, the first bearing pad, the third bearing pad, the second bearing pad, the second bearing pad, the worm gear fixing ring, the third bearing and lock the bearing inner pressure ring, test the starting friction torque and radial runout of the trapezoidal screw, and judge the bearing preload condition and installation quality according to the starting friction force and radial runout values; S4. Measure the distance h3 between the left end face of the third bearing and the left end face of the worm gear box and the thickness h4 of the inner ring of the third bearing, and calculate that the distance between the left end face of the worm gear fixing ring installed under the formal bearing and the left end face of the worm gear box is H2=h3+h4; S5. Calculate the difference △=H1-H2, grind off the height L2 of the second bearing pad by the △ value and ensure that the parallelism of the two end surfaces of the second bearing pad is better than 0.003mm.

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