An adsorption pump with anti-powdering ability for space hydrogen atomic clock

Abstract

The present invention discloses an adsorption pump with anti-powdering ability for a space hydrogen atomic clock, comprising an adsorption pump housing, an adsorption pump chassis, and a plurality of groups of air suction units arranged on the adsorption pump chassis, the air suction units comprising a tubular bracket, a gasket, an air suction agent sheet, and a heating device; the tubular bracket is arranged in four layers from the inner circle to the outer circle and arranged on the adsorption pump chassis, and the air suction agent sheets are arranged in series through the tubular bracket to form an air suction unit; the air suction agent sheets are separated by gaskets, and the top of the air suction agent sheet group is fixed by a fixing nut; a heating wire is arranged in the tubular bracket. The present invention improves the surface strength of the air suction agent, achieves high air suction performance, and does not cause the air suction sheet to fall off; and has the characteristics of long service life, non-magnetic, no need for continuous power supply of an additional power supply, and the air suction process can be carried out at room temperature for hydrogen, etc., which effectively maintains the high vacuum system of the hydrogen atomic clock and solves the problems existing in the space hydrogen atomic clock.

Description

Technical Field

[0001] The invention relates to the field of electronic vacuum, and in particular to an adsorption pump with anti-powdering capability used in a space hydrogen atomic clock. Background Art

[0002] The hydrogen atomic clock is very important to the satellite navigation system. Its high-precision timing and time frequency standards can provide effective "time scale / positioning" support for the satellite navigation system. It is also called the heart of the satellite. It is used on the European "Galileo" satellite, the American "GPS" satellite, the Russian "GLONASS" satellite and the Chinese Beidou satellite. It is a key component to ensure the high-precision navigation of the satellite.

[0003] After the hydrogen atoms complete the energy level transition, hydrogen atoms of different energy levels need to be absorbed and removed by the hydrogen absorbing material to maintain the vacuum and stability of the hydrogen atomic clock. However, in the current adsorption pump, the getter sheet has the phenomenon of surface particle shedding. In addition, the excessive absorption of hydrogen will cause stress concentration inside the getter material and form small cracks. These small cracks will continue to expand as the hydrogen absorption continues, and eventually break into small particles, threatening the service life of the hydrogen atomic clock. Summary of the invention

[0004] The purpose of the present invention is to provide an adsorption pump which is not easy to break and shed powder and has anti-powdering ability and is used in a space hydrogen atomic clock.

[0005] The object of the present invention is achieved as follows: an adsorption pump with anti-powdering ability for a space hydrogen atomic clock, comprising an adsorption pump housing, an adsorption pump chassis, and a plurality of groups of air suction units arranged on the adsorption pump chassis, wherein the air suction units comprise a tubular support, a gasket, an air suction agent sheet, and a heating device; the tubular support is arranged in four layers from the inner circle to the outer circle and is arranged on the adsorption pump chassis, and the tubular support is penetrated and serially provided with air suction agent sheets to form an air suction unit; the air suction agent sheets are separated by gaskets, and the top of the air suction agent sheet group is fixed by a fixed plate. The tubular bracket is fixed with a fixed nut; a heating wire is arranged in the tubular bracket; the getter sheet is composed of one or more getter sheets of Zr-V-Fe, Ti-Mo, V-Zr-Ti with a Zr-Cu alloy coating, and the air intake unit is composed of 11 getter sheets of Zr-V-Fe, Ti-Mo, V-Zr-Ti with a Zr-Cu alloy coating connected in series; the composition of the Zr-Cu alloy is Zr100-XCuX, wherein 0.5≤X<25 (wt%), and the thickness of the coating is 50-150 microns.

[0006] Preferably, the adsorption pump housing, adsorption pump chassis and gasket are all made of titanium-aluminum alloy with a thickness of 0.5-2 mm.

[0007] Preferably, the adsorption pump shell is in the shape of a hollow annular cylinder with an outer diameter of 203 mm, an inner diameter of 90 mm and a height of 40 mm, and is welded with a disc bottom plate with an outer diameter of 203 mm and an inner diameter of 40 mm.

[0008] Preferably, multiple tubular supports of the air suction unit are installed on the adsorption pump chassis, and 9 layers of air suction units are arranged on the chassis from the inner diameter to the outer diameter, the first layer has 25 air suction units, the second to ninth layers have 30 air suction units respectively, and there are 265 air suction units in total.

[0009] Preferably, the tubular support is a hollow structure, the inner hollow structure is equipped with a heating wire, and the material of the heating wire is Ni-Cr.

[0010] Preferably, the getter sheet at the top is fastened by a titanium-aluminum alloy fastening nut to prevent the getter sheet connected in series on the titanium-aluminum alloy tubular bracket from shaking.

[0011] Compared with the prior art, the present invention is beneficial in that a gradient structure Zr-Cu alloy coating is coated on the surface of the getter sheet Zr-V-Fe, Ti-Mo, V-Zr-Ti, and then the film layer is sintered and fixed on the surface of the getter sheet Zr-V-Fe, Ti-Mo, V-Zr-Ti substrate in a vacuum sintering furnace to obtain a new high-strength Zr-V-Fe, Ti-Mo, V-Zr-Ti getter sheet with anti-powdering ability, see attached Figure 1 . Because the pores of the Zr-Cu alloy coating film layer are smaller than the particle size of the Zr-V-Fe, Ti-Mo, and V-Zr-Ti matrix getter sheet particles, the possibility of the matrix Zr-V-Fe, Ti-Mo, and V-Zr-Ti getter sheet particles falling off from the pores of the film layer is blocked. In this way, the surface strength of the getter is improved, and high getter performance is achieved without the getter sheet powder falling off. It can also absorb impurity gases such as (low-energy H, CO, O2, H2O, CO2, etc.) in the service environment of the hydrogen atomic clock. It has the characteristics of long service life, non-magnetic, no need for additional power supply, and hydrogen can be absorbed at room temperature. The process can effectively maintain the high vacuum system of the hydrogen atomic clock and solve the problems of the space hydrogen atomic clock. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 It is a schematic structural diagram of the air intake unit of the present invention.

[0014] Figure 3 It is a schematic structural diagram of the getter sheet with Zr-Cu alloy coating according to the present invention.

[0015] Figure 4 These are surface microscopic morphologies of the getter sheets coated with Cu at contents of 5%, 10% and 15% respectively and subjected to vacuum sintering.

[0016] Figure 5 This is a distribution diagram of the air intake unit of the present invention.

[0017] Among them, 1 is a tubular bracket, 2 is a getter sheet, 3 is a gasket, 4 is a heating device, 5 is a fixing nut, 6 is an adsorption pump housing, and 7 is an adsorption pump chassis. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] like Figure 1-5 As shown, an adsorption pump with anti-powdering ability for a space hydrogen atomic clock, the getter used is one or more combinations of Zr-V-Fe, Ti-Mo, V-Zr-Ti getter sheets with a Zr-Cu coating on the surface, wherein the coating alloy component is Zr 100-X Cu X , wherein 0.5≦X<25 (wt%), the thickness of the coating is 50-150 microns; 11 getter sheets 1 (Zr-V-Fe, Ti-Mo, V-Zr-Ti) are taken, loaded on a tubular support, and the 11 getter sheets are separated from each other by gaskets and strung together to form an air-intake unit; each unit is assembled by mixing one or two or three getter sheets of Zr-V-Fe, Ti-Mo, V-Zr-Ti, and the air-intake unit structure is as follows Figure 2 ; Adsorption pump such as Figure 1 , consists of an adsorption pump housing, an adsorption pump chassis, an absorbent sheet (one of Zr-V-Fe, Ti-Mo, V-Zr-Ti absorbent sheets or a mixed assembly of two or three absorbent sheets), a gasket, a titanium-aluminum alloy fixing nut, a Ni-Cr heating wire, and a tubular bracket; the tubular bracket has an inner diameter of 3.5mm and a titanium-aluminum alloy tube with a height of 40mm. A Ni-Cr resistance wire can be placed inside the tubular bracket for activating the absorbent unit.

[0020] Implementation Example 1

[0021] Zr powder and Cu powder were mixed, and the mass ratio of Zr powder was 95% and the mass ratio of Cu powder was 5% during the mixing; Zr and Cu powder were mixed with ether, and ball milled for 12 hours to prepare Zr-Cu alloy powder slurry, which was coated on Zr-V-Fe getter sheet. Figure 3Then, the Zr-V-Fe getter sheet coated with Zr95Cu5 alloy powder slurry was vacuum sintered. The sintering process was 900℃ vacuum insulation for 60min to prepare a Zr-V-Fe getter sheet with Zr94Cu6 alloy coating. Sintering necks were generated between the particles on the surface of the coating film after vacuum sintering. Figure 4 (a) Circle mark, which can ensure that the air-inhaling sample has high mechanical properties and anti-powdering ability, and no particles are found on the surface of the film. In addition, the surface of the film has sufficient porosity, and these pore structures can ensure that the sample has high air-inhaling performance. These air-inhaling sheets are assembled on Figure 2 In the process, an air suction unit is formed, and the air suction unit is installed in the adsorption pump block to prepare an adsorption pump such as Figure 1 .

[0022] Implementation Example 2

[0023] The Zr powder and the Cu powder are mixed, and the mass ratio of the Zr powder is 90% and the mass ratio of the Cu powder is 10% during the mixing; the Zr and Cu powders are mixed with ether, ball-milled for 12 hours to prepare a Zr-Cu alloy powder slurry, and coated on a Zr-V-Fe getter sheet; and then the Zr-coated 95 Cu 5 The Zr-V-Fe getter sheet of the alloy powder slurry was vacuum sintered, and the sintering process was 900℃ vacuum insulation for 60min to prepare a Zr 90 Cu 10 For the Zr-V-Fe alloy coated getter sheet, a sintering neck is also formed between the particles on the surface of the coating film after vacuum sintering, and the size of the sintering neck is larger than that of the Zr 94 Cu 6 Sintering neck of alloy coating layer, see Figure 4 (b), no particles were found on the surface of the film. Moreover, the porosity of the film surface was lower than that of Zr 94 Cu 6 The alloy coating has a small porosity, which means that its air absorption performance is not as good as Figure 4 (a) has better air absorption performance, but its mechanical properties are better than those of the air absorption samples. Figure 4 (a), similarly, the sintered structure of sample 4(b) can ensure that the getter sample has high mechanical properties and anti-powdering ability. Figure 2 In the process, an air suction unit is formed, and the air suction unit is installed in the adsorption pump block to prepare an adsorption pump such as Figure 1 .

[0024] Implementation Example 3

[0025] Zr powder was mixed with Cu powder. During the mixing, the mass ratio of Zr powder was 85% and the mass ratio of Cu powder was 15%. Zr and Cu powder were mixed with ether and ball milled for 12 hours to prepare Zr-Cu alloy powder slurry, which was then coated on Zr-V-Fe getter sheet. 85 Cu 15 The Zr-V-Fe getter sheet of the alloy powder slurry was vacuum sintered. The sintering process was 900℃ vacuum insulation for 60min to prepare a Zr-V-Fe getter sheet with Zr85Cu15 alloy coating. Sintering necks were also generated between the particles on the surface of the coating film after vacuum sintering, and the size of the sintering necks was larger than that of the Zr 94 Cu 6 and Zr 90 Cu 10 Sintering neck of alloy coating layer, see Figure 4 (c), no particles were found on the surface of the film. Moreover, the porosity of the film surface was lower than that of Zr 94 Cu 6 The alloy coating has a small porosity, which means that its air absorption performance is not as good as Figure 4 (a) and Figure 4 (b) has better air absorption performance, but the mechanical properties of the air absorption sample are better than Figure 4 (a) and Figure 4 (b) Similarly, Figure 4 (c) The sintered structure of the sample can ensure that the getter sample has high mechanical properties and anti-powdering ability. Figure 2 In the process, an air suction unit is formed, and the air suction unit is installed in the adsorption pump block to prepare an adsorption pump such as Figure 1 .

[0026] The above-described embodiments are merely descriptions of preferred implementations of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made by ordinary persons in the art to the technical solution of the present invention should fall within the protection scope of the present invention, and the technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. An adsorption pump with anti-powdering capability for a space hydrogen atomic clock, comprising an adsorption pump housing, an adsorption pump chassis, and a plurality of air suction units arranged on the adsorption pump chassis, characterized in that: The air intake unit comprises a tubular support, a gasket, an air intake agent sheet, and a heating device; the tubular support is arranged in four layers from the inner circle to the outer circle and is arranged on the chassis of the adsorption pump, and the tubular support is penetrated by the air intake agent sheets arranged in series to form an air intake unit; the air intake agent sheets are separated by gaskets, and the top of the air intake agent sheet group is fixed by a fixing nut; a heating wire is arranged in the tubular support; the air intake agent sheet is a Zr-V-Fe air intake sheet with a Zr-Cu alloy coating, and the air intake unit is composed of 11 Zr-V-Fe air intake sheets with a Zr-Cu alloy coating connected in series; the Cu content in the Zr-Cu alloy is 5wt%-15wt%, and the thickness of the coating is 50-150 microns; The Zr-Cu alloy coating steps are as follows: Mixing Zr powder and Cu powder, wherein the mass ratio of Zr powder is 85wt%-95wt% and the mass ratio of Cu powder is 5wt%-15wt%; Zr and Cu powders were mixed with ether and ball-milled for 12 h to prepare Zr-Cu alloy powder slurry, which was then coated on a Zr-V-Fe getter sheet; Then, the getter sheet coated with the Zr-Cu alloy powder slurry is subjected to vacuum sintering, and the sintering process is vacuum insulation at 900° C. for 60 minutes to prepare a getter sheet with a Zr-Cu alloy coating; The getter sheet forms sintering necks between particles on the surface of the coating film layer after the Zr-Cu alloy coating is vacuum sintered.

2. The adsorption pump with anti-powdering capability for use in a space hydrogen atomic clock according to claim 1, characterized in that: The adsorption pump housing, the adsorption pump chassis and the gasket are all made of titanium-aluminum alloy with a thickness of 0.5-2mm.

3. The adsorption pump with anti-powdering capability for use in a space hydrogen atomic clock according to claim 1, characterized in that: The adsorption pump shell is in the shape of a hollow annular cylinder with an outer diameter of 203 mm, an inner diameter of 90 mm and a height of 40 mm, and is welded with a disc chassis with an outer diameter of 203 mm and an inner diameter of 40 mm.

4. The adsorption pump with anti-powdering capability for use in a space hydrogen atomic clock according to claim 1, characterized in that: A plurality of tubular supports of the air suction unit are installed on the chassis of the adsorption pump. Nine layers of air suction units are arranged on the chassis from the inner diameter to the outer diameter. The first layer has 25 air suction units, and the second to ninth layers have 30 air suction units respectively, with a total of 265 air suction units.

5. The adsorption pump with anti-powdering capability for a space hydrogen atomic clock according to claim 1, characterized in that: The tubular support is a hollow structure, and a heating wire is installed inside the hollow structure. The material of the heating wire is Ni-Cr.

6. The adsorption pump with anti-powdering capability for a space hydrogen atomic clock according to claim 1, characterized in that: The getter sheet at the top is fastened by a titanium-aluminum alloy fastening nut to prevent the getter sheet connected in series on the titanium-aluminum alloy tubular bracket from shaking.

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