Method for hardening dynamic pressure sliding bearing, dynamic pressure sliding bearing, and x-ray tube

Abstract

The invention relates to a hardening method of a dynamic pressure sliding bearing, the dynamic pressure sliding bearing and an X-ray tube. According to the hardening method of the dynamic pressure sliding bearing, the dynamic pressure sliding bearing comprises a core shaft and a shaft sleeve arranged outside the core shaft in a sleeving mode, a gap is formed between the core shaft and the shaft sleeve, the gap is filled with dynamic pressure fluid, and the hardening method of the dynamic pressure sliding bearing comprises the steps that a to-be-hardened part is placed in a vacuum cavity; the to-be-hardened part comprises at least one of the mandrel and the shaft sleeve; non-metal ions are emitted through an ion source, the non-metal ions are accelerated under the action of an accelerating electric field so as to bombard the to-be-hardened surface of the to-be-hardened part, the to-be-hardened surface comprises the outer circumferential face of the mandrel and / or the inner circumferential face of the shaft sleeve, and the non-metal ions comprise carbon ions and / or nitrogen ions. According to the hardening method of the dynamic pressure sliding bearing, the surface hardness and strength of the dynamic pressure sliding bearing can be improved, so that the dynamic pressure sliding bearing has more excellent wear resistance and high temperature resistance.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a hardening method of a hydrodynamic sliding bearing, a hydrodynamic sliding bearing and an X-ray tube. Background Art

[0002] A hydrodynamic sliding bearing usually includes a core shaft and a sleeve sleeved on the outside of the core shaft, and the gap between the two is filled with hydrodynamic fluid to support the bearing to rotate without contact at high speeds. This type of hydrodynamic sliding bearing is usually set at the anode position of the X-ray tube, wherein the position of the core shaft is fixed and the sleeve can rotate relative to the core shaft. Since this type of bearing uses hydrodynamic fluid as its friction medium, it changes the hard contact friction state between the ball and the bearing parts in the conventional bearing, and thus can significantly improve the wear resistance and friction reduction performance of the sleeve during high-speed operation. However, in the related art, during the start-stop process of the sliding bearing, the large change in speed may cause the hydrodynamic fluid to be unable to provide sufficient supporting force to separate the core shaft and the sleeve, and solid friction may occur between the two. In order to cope with this situation, there are higher requirements for the surface wear resistance of such bearings. Therefore, how to improve the surface hardness and strength of such bearings is one of the technical problems that need to be solved urgently. Summary of the invention

[0003] Based on this, it is necessary to provide a hardening method for a hydrodynamic sliding bearing to improve the surface hardness and strength of the hydrodynamic sliding bearing so as to make it have better wear resistance and high temperature resistance.

[0004] A method for hardening a dynamic pressure sliding bearing, the dynamic pressure sliding bearing comprising a core shaft and a sleeve sleeved outside the core shaft, a gap is provided between the core shaft and the sleeve, and the gap is filled with a dynamic pressure fluid, the method for hardening the dynamic pressure sliding bearing comprising:

[0005] Placing the workpiece to be hardened in a vacuum chamber, wherein the workpiece to be hardened includes at least one of the mandrel and the sleeve;

[0006] Non-metallic ions are emitted through an ion source, so that the non-metallic ions are accelerated under the action of an accelerating electric field to bombard the surface to be hardened of the part to be hardened, wherein the surface to be hardened includes the outer circumference of the core shaft and / or the inner circumference of the sleeve, and the non-metallic ions include carbon ions and / or nitrogen ions.

[0007] In one embodiment, the ion source of the nitrogen ions is a gas ion source, and the ion source of the carbon ions is a solid ion source.

[0008] In one embodiment, the method of infiltrating the nitrogen ions and the carbon ions into the surface to be hardened is:

[0009] The solid ion source is placed in the vacuum chamber, nitrogen or nitrogen-argon mixed gas is introduced into the vacuum chamber to make the pressure in the vacuum chamber reach a preset stable value, the nitrogen ions are ionized by the gas ion source, and the carbon ions are ionized by the solid ion source, and the nitrogen ions and the carbon ions are accelerated to bombard the surface to be hardened.

[0010] In one embodiment, before placing the workpiece to be hardened in the vacuum chamber, the method further comprises:

[0011] The dynamic pressure sliding bearing is subjected to finish machining, and the finish machining method includes: forming a spiral groove on the outer peripheral surface of the core shaft, wherein the spiral groove is connected to the gap for passing the dynamic pressure fluid.

[0012] In one embodiment, when the non-metallic ions are emitted by the ion source to bombard the surface to be hardened, the temperature of the workpiece to be hardened is controlled to be lower than its tempering temperature.

[0013] In one embodiment, the method of controlling the temperature of the hardened part includes:

[0014] Adjust the ion flow density of the non-metallic ions, and / or adjust the duration of the non-metallic ions bombarding the surface to be hardened, and / or adjust the internal voltage of the ion source, and / or adjust the voltage of the power supply used to form the accelerating electric field.

[0015] The hardening method of the above-mentioned dynamic pressure sliding bearing emits carbon ions and / or nitrogen ions through an ion source in a vacuum environment, and the carbon ions and / or nitrogen ions are accelerated under the action of an accelerating electric field and penetrate into the outer peripheral surface of the core shaft and / or the inner peripheral surface of the sleeve. The carbon ions and / or nitrogen ions are penetrated into the outer peripheral surface of the core shaft and / or the inner peripheral surface of the sleeve, and the carbon ions and / or nitrogen ions can form bonds with the metal ions on the outer peripheral surface of the core shaft and / or the inner peripheral surface of the sleeve, and migrate after bonding, changing the crystal structure and bonding mode of the material, thereby increasing the concentration of carbides and / or nitrides in the hardening phase of the outer peripheral surface of the core shaft and / or the inner peripheral surface of the sleeve, thereby forming a surface with higher hardness and higher strength on a macro scale, and thus having better wear resistance and high temperature resistance.

[0016] The present application also proposes a hydrodynamic sliding bearing, the hydrodynamic sliding bearing comprising:

[0017] Mandrel;

[0018] A sleeve is sleeved on the outside of the core shaft, and a gap is formed between the core shaft and the sleeve, and the gap is filled with a dynamic pressure fluid;

[0019] The outer circumferential surface of the mandrel and / or the inner circumferential surface of the sleeve are configured to be infiltrated with non-metallic ions under a vacuum environment to form a surface hardening layer, wherein the non-metallic ions include carbon ions and / or nitrogen ions.

[0020] In one embodiment, the outer circumferential surface of the core shaft is provided with a spiral groove, and the groove wall of the spiral groove is configured to infiltrate non-metallic ions under a vacuum environment to form a surface hardening layer, and the non-metallic ions include carbon ions and / or nitrogen ions.

[0021] In one embodiment, the material of the dynamic pressure fluid is gallium, mercury or gallium-indium-tin alloy.

[0022] In the above-mentioned hydrodynamic sliding bearing, the outer circumferential surface of the core shaft and / or the inner circumferential surface of the sleeve are configured to infiltrate carbon ions and / or nitrogen ions under a vacuum environment. The carbon ions and / or nitrogen ions can form bonds with the metal ions on the outer circumferential surface of the core shaft and / or the inner circumferential surface of the sleeve, and migrate after bonding, changing the crystal structure and bonding mode of the material, thereby increasing the concentration of carbides and / or nitrides in the hardened phase on the outer circumferential surface of the core shaft and / or the inner circumferential surface of the sleeve, forming a surface hardening layer, and forming a surface with higher hardness and higher strength on a macro scale, thereby improving wear resistance and high temperature resistance.

[0023] The present application also provides an X-ray tube, comprising the above-mentioned dynamic pressure sliding bearing.

[0024] The X-ray tube mentioned above, by applying the above-mentioned dynamic pressure sliding bearing, can reduce the frequency of disassembly and replacement due to severe wear of the dynamic pressure sliding bearing, thereby reducing the repair cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of a hydrodynamic sliding bearing in one embodiment of the present application.

[0026] Figure 2 for Figure 1 A partial enlarged view of the middle spiral groove.

[0027] Figure 3 It is a schematic structural diagram of a hardening device for a hydrodynamic sliding bearing in one embodiment of the present application.

[0028] Figure 4 It is a schematic structural diagram of a hardening device for a hydrodynamic sliding bearing in another embodiment of the present application.

[0029] Reference numerals:

[0030] Mandrel 100, spiral groove 110; sleeve 200; gap 300;

[0031] Vacuum chamber 400 , vacuum tube 410 , turntable 420 , fixed gear 431 , rotating gear 432 , mandrel tooling 440 , sleeve tooling 450 , gas ion source 460 , solid ion source 470 . DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0033] In the description of the present application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0034] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, if the term "plurality" appears, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0035] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] In the present application, unless otherwise clearly specified and limited, if there is a description that a first feature is "above" or "below" a second feature, etc., or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0037] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only implementation method.

[0038] See also Figure 1 and Figure 2 , briefly describe the structure of the hydrodynamic sliding bearing. Figure 1 is a schematic structural diagram of a hydrodynamic sliding bearing in an embodiment of the present application, Figure 2 for Figure 1 The hydrodynamic sliding bearing comprises a core shaft 100 and a sleeve 200 sleeved on the outside of the core shaft 100, a gap 300 is provided between the core shaft 100 and the sleeve 200, and the gap 300 is filled with hydrodynamic fluid.

[0039] See also Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the structure of a hardening device for a dynamic pressure sliding bearing in one embodiment of the present application. Figure 4 The hardening method of the dynamic pressure sliding bearing provided in one embodiment of the present application includes:

[0040] Placing a workpiece to be hardened in a vacuum chamber 400, wherein the workpiece to be hardened includes at least one of a mandrel 100 and a sleeve 200;

[0041] Non-metallic ions are emitted through an ion source and accelerated under the action of an accelerating electric field to bombard the surface to be hardened of the part to be hardened, the surface to be hardened includes the outer circumference of the core shaft 100 and / or the inner circumference of the sleeve 200, and the non-metallic ions include carbon ions and / or nitrogen ions.

[0042] The hardening method of the above-mentioned dynamic pressure sliding bearing emits carbon ions and / or nitrogen ions through an ion source in a vacuum environment, and the carbon ions and / or nitrogen ions are accelerated under the action of an accelerating electric field and penetrate into the outer peripheral surface of the mandrel 100 and / or the inner peripheral surface of the sleeve 200. The carbon ions and / or nitrogen ions are penetrated into the outer peripheral surface of the mandrel 100 and / or the inner peripheral surface of the sleeve 200, and the carbon ions and / or nitrogen ions can form bonds with the metal ions on the outer peripheral surface of the mandrel 100 and / or the inner peripheral surface of the sleeve 200, and migrate after bonding, changing the crystal structure and bonding mode of the material, thereby increasing the concentration of carbides and / or nitrides in the hardened phase of the outer peripheral surface of the mandrel 100 and / or the inner peripheral surface of the sleeve 200, thereby forming a surface with higher hardness and higher strength on a macro scale, and thus having better wear resistance and high temperature resistance.

[0043] Specifically, when the part to be hardened is the mandrel 100, the corresponding surface to be hardened is the outer circumference of the mandrel 100. When the part to be hardened is the sleeve 200, the corresponding surface to be hardened is the inner circumference of the sleeve 200. When the parts to be hardened are the mandrel 100 and the sleeve 200, the corresponding surfaces to be hardened are the outer circumference of the mandrel 100 and the inner circumference of the sleeve 200.

[0044] In some embodiments, the ion source of nitrogen ions is a gas ion source 460 , and the ion source of carbon ions is a solid ion source 470 .

[0045] Specifically, when nitrogen ions need to be infiltrated into the surface to be hardened, the ion source uses a gas ion source 460, and nitrogen is passed into the gas ion source 460. The nitrogen is ionized to form nitrogen ions under the action of the high electromagnetic field in the gas ion source 460. An accelerating electric field is provided in the vacuum chamber 400, and the nitrogen ions ejected from the gas ion source 460 are accelerated under the action of the accelerating electric field, bombarding the surface to be hardened, thereby achieving nitriding.

[0046] When carbon ions need to be infiltrated into the surface to be hardened, the ion source is a solid ion source 470. The carbon atoms on the graphite target in the solid ion source 470 are evaporated and ionized to form carbon ions. The carbon ions ejected from the solid ion source 470 are accelerated under the action of the accelerating electric field and bombard the surface to be hardened, thereby achieving carburization.

[0047] Furthermore, in some embodiments, the gas ion source 460 may be a Hall ion source, an anode layer ion source, a Kaufman ion source, or the like.

[0048] In some embodiments, solid ion source 470 may be a Melvar ion source.

[0049] Typically, the voltage applied by the solid ion source 470 during ionization is much greater than that of the gas ion source 460. Therefore, the energy obtained by the carbon ions after ionization is also much greater than that of the nitrogen ions. The directionality of the carbon ions when bombarding the workpiece to be hardened is stronger than that of the nitrogen ions. Therefore, the carbon ions can be injected into a deeper position in the workpiece to be hardened, and the depth of the surface hardened layer formed is greater.

[0050] Preferably, in some embodiments, when the surface to be hardened is the inner circumference of the sleeve 200 , the non-metal ions used to achieve hardening are nitrogen ions.

[0051] It is understandable that the inner circumference of the sleeve 200 is not easily reached by ions due to the obstruction. Therefore, when hardening the sleeve 200, nitrogen ions with weaker directionality are preferred so that more ions can reach the inner circumference of the sleeve 200 to ensure a better hardening effect.

[0052] Alternatively, in some embodiments, the non-metal ions used to achieve hardening are nitrogen ions and carbon ions, which is carbonitriding.

[0053] In some embodiments, when the surface to be hardened is the outer peripheral surface of the core shaft 100, the non-metallic ions used for hardening are carbon ions, or the non-metallic ions used for hardening are nitrogen ions, or the non-metallic ions used for hardening are nitrogen ions and carbon ions.

[0054] Since the outer peripheral surface of the core shaft 100 is not blocked, any of the above-mentioned non-metallic ions can be selected to harden it.

[0055] Generally, compared with carburizing or nitriding alone, carbonitriding forms a surface hardened layer with better hardness, wear resistance, corrosion resistance, bending strength and contact fatigue strength. Therefore, in a more preferred embodiment, whether the surface to be hardened is the outer peripheral surface of the mandrel 100 or the inner peripheral surface of the sleeve 200, carbonitriding is performed to infiltrate nitrogen ions and carbon ions into the surface to be hardened, thereby optimizing the hardening effect to a greater extent. Of course, in other embodiments, nitriding and carburizing may be performed in sequence, or carburizing and nitriding may be performed in sequence, and the hardening effect at this time is also better than that of nitriding or carburizing alone.

[0056] In some embodiments, the method of jointly infiltrating nitrogen ions and carbon ions into the surface to be hardened is: placing a solid ion source 470 in a vacuum chamber 400, introducing nitrogen gas or a nitrogen-argon mixed gas into the vacuum chamber 400, so that the pressure in the vacuum chamber 400 reaches a preset stable value, using the gas ion source 460 to ionize nitrogen ions, and using the solid ion source 470 to ionize carbon ions, and accelerating the nitrogen ions and carbon ions to bombard the surface to be hardened.

[0057] Specifically, a solid ion source 470 and a gas ion source 460 are simultaneously arranged in the vacuum chamber 400, so that the ejection ports of the solid ion source 470 and the gas ion source 460 are located in the vacuum chamber 400. Nitrogen or a nitrogen-argon mixed gas is introduced into the gas ion source 460 in the vacuum chamber 400, and is ionized in the gas ion source 460 to form nitrogen ions. The carbon atoms on the graphite target in the solid ion source 470 are evaporated and ionized to form carbon ions. The formed nitrogen ions and carbon ions are accelerated under the action of the accelerating electric field, bombarding the surface to be hardened, thereby realizing carbonitriding.

[0058] In some embodiments, the method of setting the accelerating electric field in the vacuum chamber 400 is: the workpiece to be hardened is electrically connected to the negative electrode of the power supply, and the positive electrode of the power supply is grounded, so that an accelerating electric field with electric field lines pointing to the workpiece to be hardened is formed near the workpiece to be hardened. Since nitrogen and carbon vapor are ionized into positive ions by electrons in the ion source, the positive ions will move along the direction of the electric field lines in the accelerating electric field, accelerating to bombard the surface to be hardened.

[0059] Specifically, the workpiece to be hardened is fixedly mounted on a conductive tooling, for example, the mandrel 100 is mounted on the mandrel tooling 440, and the sleeve 200 is mounted on the sleeve tooling 450. The tooling can be electrically connected to the negative pole of the power supply to form an accelerating electric field; or the turntable 420 for mounting the tooling can be electrically connected to the negative pole of the power supply to form an accelerating electric field. When the sleeve 200 is hardened alone, it can be used Figure 4 The hardening device shown is complete. When hardening the mandrel 100 alone, it can be used Figure 3 The hardening device shown is completed. When the mandrel 100 and the sleeve 200 are hardened at the same time, Figure 3 or Figure 4 The device is improved by simultaneously setting the mandrel tooling 440 and the sleeve tooling 450 in the same vacuum chamber 400.

[0060] In some embodiments, before placing the workpiece to be hardened in the vacuum chamber 410 , the workpiece to be hardened is cleaned.

[0061] Specifically, in some embodiments, when cleaning the hardened part, the cleaning agent used is anhydrous ethanol, hydrocarbon cleaning agent or acetone.

[0062] Specifically, wipe the surface of the hardened part with anhydrous ethanol using a clean dust-free cloth or absorbent cotton. Then, use a hydrocarbon cleaning agent or acetone to ultrasonically clean the hardened part. The cleaning can be repeated multiple times, with each cleaning time not less than 5 minutes, to achieve a better cleaning effect. After cleaning, dry in a vacuum drying oven.

[0063] After the above cleaning, dirt and impurities on the surface of the hardened part can be removed. Based on this, preferably, in some embodiments, before emitting non-metallic ions through an ion source to bombard the surface to be hardened, the process also includes: cleaning the hardened part in the vacuum chamber by argon ion etching.

[0064] Specifically, after the hardened part is placed in the vacuum chamber 400, it is cleaned by argon ion etching. This cleaning can remove some oxides and impurities with strong adhesion attached to the surface of the hardened part, exposing a relatively pure surface, so that the subsequent ion penetration effect is better.

[0065] Preferably, after placing the workpiece to be hardened in the vacuum chamber 400, the vacuum chamber 400 is first heated so that some volatile impurities attached to the surface of the workpiece to be hardened can be removed by volatilization. In addition, the temperature of the workpiece to be hardened after heating is relatively high, and the cleaning effect of argon ion etching cleaning is also better. In some embodiments, the air in the vacuum chamber 400 can be heated to 200 degrees to 250 degrees. When in this temperature range, not only can the volatile impurities be volatilized more thoroughly, but also the internal crystal phase structure of the workpiece to be hardened can be prevented from changing due to excessive temperature.

[0066] See also Figure 1 and Figure 2 In some embodiments, before placing the hardened part in the vacuum chamber 410, the process further includes: finishing the hydrodynamic sliding bearing. The finishing process includes: forming a spiral groove 110 on the outer peripheral surface of the mandrel 100, wherein the spiral groove 110 is connected to the gap 300 for passing the hydrodynamic fluid.

[0067] Specifically, the above-mentioned finishing process is completed before the hardened part is cleaned outside the vacuum chamber 410. The depth of the formed spiral groove 110 ranges from 10 μm to 50 μm. By forming the spiral groove 110, the dynamic pressure fluid between the mandrel 100 and the sleeve 200 can flow more smoothly, and the sleeve 200 can rotate more smoothly relative to the mandrel 100.

[0068] See also Figure 3 and Figure 4 In some embodiments, when non-metallic ions are emitted from an ion source to bombard the surface to be hardened, the temperature of the workpiece to be hardened is controlled to be lower than its tempering temperature.

[0069] Specifically, by controlling the parameters of the heating element disposed in the vacuum chamber 400, the temperature of the air in the vacuum chamber 400 is changed, thereby changing the temperature of the part to be hardened. As mentioned above, before hardening, the dynamic pressure sliding bearing is finely processed. During fine processing, in addition to mechanical processing, the dynamic pressure sliding bearing is also subjected to heat treatment, such as tempering. Through tempering, the mechanical properties of the dynamic pressure sliding bearing are made better. During the hardening process, the temperature of the part to be hardened is lower than the tempering temperature during the previous fine processing, which can prevent the part to be hardened from tempering again during the hardening process, ensure the stability of its internal crystal phase structure, and ensure that the hardening process does not reduce the hardness and precision of the part to be hardened.

[0070] During the hardening process, on the one hand, the heating element in the vacuum chamber 400 works to increase the temperature of the surface of the hardened part. On the other hand, when the non-metallic ions bombard the surface to be hardened, the temperature of the surface of the hardened part will also increase.

[0071] Based on this, in some embodiments, the method of controlling the temperature of the workpiece to be hardened includes: adjusting the ion flow density of the non-metallic ions, and / or adjusting the duration of the bombardment of the surface to be hardened by the non-metallic ions, and / or adjusting the internal voltage of the ion source, and / or adjusting the voltage of the power supply used to form an accelerating electric field.

[0072] Specifically, the method for adjusting the ion flow density of non-metallic ions includes: adjusting the intake of nitrogen gas introduced into the gas ion source 460, so that the amount and density of ionized nitrogen ions change. Adjusting the duration of the bombardment of the surface to be hardened by non-metallic ions includes: ionizing the non-metallic ions or stopping the ionization by turning on or off the ion source, thereby changing the bombardment duration. The higher the energy of the non-metallic ions, the greater the temperature rise caused when bombarding the surface of the part to be hardened. Therefore, when adjusting the internal voltage of the ion source, the energy obtained by the ionized non-metallic ions can be different, so that the temperature rise caused by the bombardment on the surface of the part to be hardened is different, thereby changing the surface temperature of the part to be hardened. Similarly, the accelerating electric field can give non-metallic ions energy, so that it accelerates to bombard the surface of the part to be hardened. Therefore, the power supply voltage used to form the accelerating electric field can be adjusted to change the electric field strength of the accelerating electric field, so that the energy obtained by the non-metallic ions is different, so that the temperature rise caused by the bombardment on the surface of the part to be hardened is different, thereby changing the surface temperature of the part to be hardened.

[0073] Preferably, in some embodiments, when the temperature of the part to be hardened is too high, firstly, a method of reducing the ion flow density of the non-metallic ions and / or shortening the duration of the bombardment of the non-metallic ions on the surface to be hardened is adopted. If the above two methods are carried out simultaneously, and the surface temperature of the part to be hardened is still too high, then consider reducing the internal voltage of the ion source and / or reducing the electric field strength of the accelerating electric field. In this way, a larger internal voltage of the ion source and / or the electric field strength of the accelerating electric field can be ensured as much as possible. Usually, the internal voltage of the ion source and the electric field strength of the accelerating electric field will affect the energy of the non-metallic ions. The higher the energy, the easier it is to inject into a deeper position in the part to be hardened, the greater the depth of the surface hardened layer formed, and the better the hardening effect. Therefore, when the above method is adopted, the non-metallic ion injection depth can be increased as much as possible while ensuring the surface temperature of the part to be hardened, thereby optimizing the hardening effect.

[0074] In some embodiments, a method for hardening a hydrodynamic sliding bearing includes:

[0075] S100 detects the size and accuracy of the hardened parts after machining and heat treatment to ensure that they meet the assembly requirements;

[0076] S200 cleans the hardened parts to remove dirt and impurities on the surface, and then dries them in a vacuum drying oven;

[0077] S300: placing the workpiece to be hardened in the vacuum chamber 400, evacuating the vacuum chamber 400, and heating the vacuum chamber 400;

[0078] S400 performs argon ion etching and cleaning on hardened parts;

[0079] S500 turns on the ion source to perform nitriding / carburizing / carbonitriding / sequential nitriding and carburizing / sequential carburizing and nitriding on the hardened parts;

[0080] S600 cools down the vacuum chamber 400;

[0081] After the temperature is lowered to 70° C. at S700 , the vacuum chamber 400 is inflated to restore the normal pressure;

[0082] S800: Open the vacuum chamber 400 and take out the workpiece to be hardened;

[0083] The S900 once again checks the size and accuracy of the workpiece to be hardened to ensure that the size and accuracy have not changed during the hardening process, and checks the internal and surface hardness of the workpiece to be hardened to verify the hardening effect.

[0084] See also Figure 3 and Figure 4In step S300, the vacuum pump is connected to the vacuum chamber 400 through the vacuum tube 410 connected to the inner cavity of the vacuum chamber 400 to achieve vacuuming. In the process of nitriding / carburizing / carbonitriding / sequential nitriding and carburizing / sequential carburizing and nitriding of the hardened part, preferably, the turntable 420 drives the tooling (mandrel tooling 440 and / or sleeve tooling 450) installed thereon to revolve, so as to achieve the revolution of the hardened part, so that it can reach the ejection port of the gas ion source 460 or the solid ion source 470, and realize the type switching of nitriding or carburizing. At the same time, the fixed gear 431 arranged on the annular turntable 420 is rotated to drive the rotating gear 432 meshed therewith to rotate, so that the tooling installed on the rotating gear 432 can rotate while rotating, thereby changing the area of ​​the hardened part facing the ejection port of the gas ion source 460 or the solid ion source 470, and realizing the switching of the hardening area. Through this method of self-rotation and revolution, the hardening process can be completed efficiently.

[0085] Several groups of specific embodiments are provided below to illustrate the parameters of the hardening process.

[0086] 1. Single nitriding

[0087] 1. Use a clean dust-free cloth or absorbent cotton to dip in anhydrous ethanol, wipe the part to be hardened, and test the final size, dimensional accuracy and hardness of the part to be hardened, record the measured values, and ensure that the size, dimensional accuracy and hardness meet the requirements.

[0088] 2. Use hydrocarbon cleaning agent or acetone to ultrasonically clean the hardened parts three times, with each cleaning time not less than 5 minutes. After cleaning, dry them in a vacuum drying oven.

[0089] 3. Place the workpiece to be hardened in the vacuum chamber 400. If the workpiece to be hardened is the mandrel 100, adjust the direction of the gas ion source 460 so that the ejection port is perpendicular to the axis of the mandrel 100 and the distance between the two is between 320 mm and 360 mm. If the workpiece to be hardened is the sleeve 200, adjust the direction of the gas ion source 460 so that the angle between the ejection port and the axis of the sleeve 200 is 30°-50° and the distance between the gas ion source 460 and the upper area of ​​the sleeve 200 is between 240 mm and 280 mm.

[0090] 4. Close the vacuum chamber 400 and evacuate it until the vacuum degree reaches 5×10 -3 Pa, set the heating temperature to 180°C-200°C, and start heating until the vacuum chamber 400 reaches the set temperature and the vacuum degree is ≤1×10 -3 Pa.

[0091] 5. Open the argon gas circuit solenoid valve, set the argon gas volume to 55sccm-65sccm, introduce high-purity argon gas into the vacuum chamber 400, set the pressure in the vacuum chamber 400 to 0.5Pa-2Pa, turn on the bias power supply, adjust its negative voltage value to 1KV, observe that the glow in the vacuum chamber 400 is normal, set the rotation speed of the turntable 420 to 5RPM, and turn on the turntable 420. The argon ion bombardment cleaning is carried out for 20 minutes, and then the argon gas and bias power supply are turned off.

[0092] 6. Check and make sure that the gas circuit of the gas ion source 460 is connected to high-purity nitrogen, open the ion source gas circuit solenoid valve, and set the gas volume to 10sccm-12sccm. Turn on the gas ion source 460, adjust the RF power to 500W, the ion source negative bias value to 23KV, and the duty cycle to 90%. Turn on the power supply of the accelerating electric field, adjust the negative bias value loaded on the turntable 420 to 10KV, and observe and determine whether the glow between the gas ion source 460 and the turntable 420 is normal and irradiated to the surface to be hardened. The part to be hardened revolves on the turntable 420 with the turntable 420 and rotates around its own axis to ensure that the cylindrical surface of the part to be hardened is evenly infiltrated with nitrogen ions.

[0093] 7. In order to ensure that the temperature of the component will not be too high when the nitrogen ions strongly bombard the surface of the hardened part, after each nitrogen ion penetration treatment for 15 minutes, pause for cooling for 40 minutes to 60 minutes, and repeat 10 times.

[0094] 8. After completing 10 nitrogen ion penetrations, turn off the gas ion source 460, the power supply of the accelerating electric field, and the nitrogen gas introduced into the gas ion source 460, turn off the turntable 420, wait for the hardened part in the vacuum chamber 400 to cool to below 60° C., fill the vacuum chamber 400 with air or nitrogen, and take out the hardened part.

[0095] 2. Single carburizing

[0096] 1. Use a clean dust-free cloth or absorbent cotton to dip in anhydrous ethanol, wipe the part to be hardened, and test the final size, dimensional accuracy and hardness of the part to be hardened, record the measured values, and ensure that the size, dimensional accuracy and hardness meet the requirements.

[0097] 2. Use hydrocarbon cleaning agent or acetone to ultrasonically clean the hardened parts three times, with each cleaning time not less than 5 minutes. After cleaning, dry them in a vacuum drying oven.

[0098] 3. Place the workpiece to be hardened in the vacuum chamber 400. If the workpiece to be hardened is the mandrel 100, adjust the direction of the ejection port of the solid ion source 470 so that it is perpendicular to the axis of the mandrel 100 and the distance between the two is between 360 mm and 450 mm. If the workpiece to be hardened is the sleeve 200, adjust the direction of the ejection port of the solid ion source 470 so that the angle between the ejection port and the axis of the sleeve 200 is 30°-50° and the distance between the solid ion source 470 and the upper area of ​​the sleeve 200 is between 280 mm and 360 mm.

[0099] 4. Close the vacuum chamber 400 and evacuate it until the vacuum degree reaches 5×10 -3 Pa, set the heating temperature to 180°C-200°C, and start heating until the vacuum chamber 400 reaches the set temperature and the vacuum degree is ≤1×10 -3 Pa.

[0100] 5. Open the argon gas circuit solenoid valve, set the argon gas volume to 55sccm-65sccm, introduce high-purity argon gas into the vacuum chamber 400, set the pressure in the vacuum chamber 400 to 0.5Pa-2Pa, turn on the bias power supply, adjust its negative voltage value to 1KV, observe that the glow in the vacuum chamber 400 is normal, set the rotation speed of the turntable 420 to 5RPM, and turn on the turntable 420. The argon ion bombardment cleaning is carried out for 20 minutes, and then the argon gas and bias power supply are turned off.

[0101] 6. Reopen the argon gas line solenoid valve, set the argon gas volume to 10sccm-15sccm, and observe that the pressure of the vacuum chamber 400 is basically stable at 2×10 -2 Pa-6×10 -2 After the gas pressure stabilizes, turn on the solid ion source 470 and adjust its internal voltage to 30KV and beam current density to 30μA / cm 2 The negative bias voltage value loaded on the turntable 420 is adjusted to 10KV, and the glow between the solid ion source 470 and the turntable 420 is observed to determine whether it is normal and irradiated to the surface to be hardened. The workpiece to be hardened revolves with the turntable 420 on the turntable 420 and rotates around its own axis to ensure that the cylindrical surface of the workpiece to be hardened is evenly infiltrated with carbon ions.

[0102] 7. In order to ensure that the temperature of the component will not be too high when the carbon ions strongly bombard the surface of the hardened part, after each carbon ion penetration treatment for 10 minutes, pause for cooling for 40 minutes to 60 minutes, and repeat 10 times.

[0103] 8. After completing 10 carbon ion penetrations, turn off the solid ion source 470, the bias power supply, the power supply of the accelerating electric field, and the argon gas introduced into the vacuum chamber 400, turn off the turntable 420, wait for the hardened part in the vacuum chamber 400 to cool to below 60° C., fill the vacuum chamber 400 with air or nitrogen, and take out the hardened part.

[0104] 3. Nitriding first and then carburizing

[0105] 1. Use a clean dust-free cloth or absorbent cotton to dip in anhydrous ethanol, wipe the part to be hardened, and test the final size, dimensional accuracy and hardness of the part to be hardened, record the measured values, and ensure that the size, dimensional accuracy and hardness meet the requirements.

[0106] 2. Use hydrocarbon cleaning agent or acetone to ultrasonically clean the hardened parts three times, with each cleaning time not less than 5 minutes. After cleaning, dry them in a vacuum drying oven.

[0107] 3. Place the workpiece to be hardened in the vacuum chamber 400. If the workpiece to be hardened is the mandrel 100, adjust the direction of the gas ion source 460 so that the ejection port is perpendicular to the axis of the mandrel 100 and the distance between the two is between 320 mm and 360 mm. If the workpiece to be hardened is the sleeve 200, adjust the direction of the gas ion source 460 so that the angle between the ejection port and the axis of the sleeve 200 is 30°-50° and the distance between the gas ion source 460 and the upper area of ​​the sleeve 200 is between 240 mm and 280 mm.

[0108] 4. Close the vacuum chamber 400 and evacuate it until the vacuum degree reaches 5×10 -3 Pa, set the heating temperature to 180°C-200°C, and start heating until the vacuum chamber 400 reaches the set temperature and the vacuum degree is ≤1×10 -3 Pa.

[0109] 5. Open the argon gas circuit solenoid valve, set the argon gas volume to 55sccm-65sccm, introduce high-purity argon gas into the vacuum chamber 400, set the pressure in the vacuum chamber 400 to 0.5Pa-2Pa, turn on the bias power supply, adjust its negative voltage value to 1KV, observe that the glow in the vacuum chamber 400 is normal, set the rotation speed of the turntable 420 to 5RPM, and turn on the turntable 420. The argon ion bombardment cleaning is carried out for 20 minutes, and then the argon gas and bias power supply are turned off.

[0110] 6. Check and make sure that the gas circuit of the gas ion source 460 is connected to high-purity nitrogen, open the ion source gas circuit solenoid valve, and set the gas volume to 10sccm-12sccm. Turn on the gas ion source 460, adjust the RF power to 500W, the ion source negative bias value to 23KV, and the duty cycle to 90%. Turn on the power supply of the accelerating electric field, adjust the negative bias value loaded on the turntable 420 to 10KV, and observe and determine whether the glow between the gas ion source 460 and the turntable 420 is normal and irradiated to the surface to be hardened. The part to be hardened revolves on the turntable 420 with the turntable 420 and rotates around its own axis to ensure that the cylindrical surface of the part to be hardened is evenly infiltrated with nitrogen ions.

[0111] 7. In order to ensure that the temperature of the component will not be too high when the nitrogen ions strongly bombard the surface of the hardened part, after each nitrogen ion penetration treatment for 15 minutes, pause for cooling for 40 minutes to 60 minutes, and repeat 5 times.

[0112] 8. After completing the nitrogen ion penetration for 5 times, turn off the gas ion source 460 and the nitrogen gas introduced into the gas ion source 460. Open the argon gas line solenoid valve, set the argon gas volume to 10sccm-15sccm, and observe that the pressure of the vacuum chamber 400 is basically stable at 2×10 -2 Pa-6×10 -2 After the gas pressure stabilizes, turn on the solid ion source 470 and adjust its internal voltage to 30KV and beam current density to 30μA / cm 2 The negative bias voltage value loaded on the turntable 420 is adjusted to 10KV, and the glow between the solid ion source 470 and the turntable 420 is observed to determine whether it is normal and irradiated to the surface to be hardened. After each carbon ion infiltration treatment for 10 minutes, the cooling is suspended for 40 minutes to 60 minutes, and the cycle is repeated 5 times.

[0113] 9. After completing 5 carbon ion infiltrations, turn off the solid ion source 470, the bias power supply, the power supply of the accelerating electric field, and the argon gas introduced into the vacuum chamber 400, turn off the turntable 420, wait for the hardened part in the vacuum chamber 400 to cool to below 60° C., fill the vacuum chamber 400 with air or nitrogen, and take out the hardened part.

[0114] 4. Carburizing first and then nitriding

[0115] 1. Use a clean dust-free cloth or absorbent cotton to dip in anhydrous ethanol, wipe the part to be hardened, and test the final size, dimensional accuracy and hardness of the part to be hardened, record the measured values, and ensure that the size, dimensional accuracy and hardness meet the requirements.

[0116] 2. Use hydrocarbon cleaning agent or acetone to ultrasonically clean the hardened parts three times, with each cleaning time not less than 5 minutes. After cleaning, dry them in a vacuum drying oven.

[0117] 3. Place the workpiece to be hardened in the vacuum chamber 400. If the workpiece to be hardened is the mandrel 100, adjust the direction of the ejection port of the solid ion source 470 so that it is perpendicular to the axis of the mandrel 100 and the distance between the two is between 360 mm and 450 mm. If the workpiece to be hardened is the sleeve 200, adjust the direction of the ejection port of the solid ion source 470 so that the angle between the ejection port and the axis of the sleeve 200 is 30°-50° and the distance between the solid ion source 470 and the upper area of ​​the sleeve 200 is between 280 mm and 360 mm.

[0118] 4. Close the vacuum chamber 400 and evacuate it until the vacuum degree reaches 5×10 -3Pa, set the heating temperature to 180°C-200°C, and start heating until the vacuum chamber 400 reaches the set temperature and the vacuum degree is ≤1×10 -3 Pa.

[0119] 5. Open the argon gas circuit solenoid valve, set the argon gas volume to 55sccm-65sccm, introduce high-purity argon gas into the vacuum chamber 400, set the pressure in the vacuum chamber 400 to 0.5Pa-2Pa, turn on the bias power supply, adjust its negative voltage value to 1KV, observe that the glow in the vacuum chamber 400 is normal, set the rotation speed of the turntable 420 to 5RPM, and turn on the turntable 420. The argon ion bombardment cleaning is carried out for 20 minutes, and then the argon gas and bias power supply are turned off.

[0120] 6. Reopen the argon gas line solenoid valve, set the argon gas volume to 10sccm-15sccm, and observe that the pressure of the vacuum chamber 400 is basically stable at 2×10 -2 Pa-6×10 -2 After the gas pressure stabilizes, turn on the solid ion source 470 and adjust its internal voltage to 30KV and beam current density to 30μA / cm 2 The negative bias voltage value loaded on the turntable 420 is adjusted to 10KV, and the glow between the solid ion source 470 and the turntable 420 is observed to determine whether it is normal and irradiated to the surface to be hardened. The workpiece to be hardened revolves with the turntable 420 on the turntable 420 and rotates around its own axis to ensure that the cylindrical surface of the workpiece to be hardened is evenly infiltrated with carbon ions.

[0121] 7. In order to ensure that the temperature of the component will not be too high when the carbon ions strongly bombard the surface of the hardened part, after each carbon ion penetration treatment for 10 minutes, pause for cooling for 40 minutes to 60 minutes, and repeat 5 times.

[0122] 8. After completing 5 carbon ion infiltrations, turn off the solid ion source 470 and the argon gas introduced into the vacuum chamber 400. Check and make sure that the gas circuit of the gas ion source 460 is connected to high-purity nitrogen, open the ion source gas circuit solenoid valve, and set the gas volume to 10sccm-12sccm. Turn on the gas ion source 460, adjust the RF power to 500W, the ion source negative bias value to 23KV, and the duty cycle to 90%. Turn on the power supply of the accelerating electric field, adjust the negative bias value loaded on the turntable 420 to 10KV, and observe and determine whether the glow between the gas ion source 460 and the turntable 420 is normal and irradiated to the surface to be hardened. After each nitrogen ion infiltration treatment for 15 minutes, pause for cooling for 40 minutes to 60 minutes, and repeat 5 times.

[0123] 9. After completing 5 nitrogen ion penetrations, turn off the gas ion source 460, the power supply of the accelerating electric field and the nitrogen gas introduced into the gas ion source 460, turn off the turntable 420, wait for the hardened workpiece in the vacuum chamber 400 to cool to below 60° C., fill the vacuum chamber 400 with air or nitrogen, and take out the hardened workpiece.

[0124] 5. Carbonitriding

[0125] 1. Use a clean dust-free cloth or absorbent cotton to dip in anhydrous ethanol, wipe the part to be hardened, and test the final size, dimensional accuracy and hardness of the part to be hardened, record the measured values, and ensure that the size, dimensional accuracy and hardness meet the requirements.

[0126] 2. Use hydrocarbon cleaning agent or acetone to ultrasonically clean the hardened parts three times, with each cleaning time not less than 5 minutes. After cleaning, dry them in a vacuum drying oven.

[0127] 3. Place the workpiece to be hardened into the vacuum chamber 400. The workpiece to be hardened includes the mandrel 100 and the sleeve 200. The mandrel 100 is carburized, and the sleeve 200 is nitrided. Adjust the direction of the jet outlet of the solid ion source 470 so that it is perpendicular to the axis of the mandrel 100, and the distance between the two is between 360 mm and 450 mm. Adjust the direction of the jet outlet of the gas ion source 460 so that the angle between the jet outlet and the axis of the sleeve 200 is 30°-50°, and the distance between the gas ion source 460 and the upper area of ​​the sleeve 200 is 240 mm-280 mm.

[0128] 4. Close the vacuum chamber 400 and evacuate it until the vacuum degree reaches 5×10 -3 Pa, set the heating temperature to 180°C-200°C, and start heating until the vacuum chamber 400 reaches the set temperature and the vacuum degree is ≤1×10 -3 Pa.

[0129] 5. Open the argon gas circuit solenoid valve, set the argon gas volume to 55sccm-65sccm, introduce high-purity argon gas into the vacuum chamber 400, set the pressure in the vacuum chamber 400 to 0.5Pa-2Pa, turn on the bias power supply, adjust its negative voltage value to 1KV, observe that the glow in the vacuum chamber 400 is normal, set the rotation speed of the turntable 420 to 5RPM, and turn on the turntable 420. The argon ion bombardment cleaning is carried out for 20 minutes, and then the argon gas and bias power supply are turned off.

[0130] 6. Reopen the argon gas circuit solenoid valve and set the argon gas volume to 8sccm-10sccm. At the same time, open the ion source gas circuit solenoid valve and set the gas volume to 8sccm-10sccm. Observe that the pressure of the vacuum chamber 400 is basically stable at 5×10 -2 Pa-9×10 - 2After the gas pressure stabilizes, turn on the solid ion source 470 and adjust its internal voltage to 30KV and beam current density to 30μA / cm 2 . Turn on the gas ion source 460, adjust the RF power to 500W, the ion source negative bias value to 23KV, and the duty cycle to 90%. Turn on the power supply of the accelerating electric field, adjust the negative bias value loaded on the turntable 420 to 10KV, and observe and judge whether the glow between the gas ion source 460 and the turntable 420 is normal and irradiated to the surface to be hardened. The workpiece to be hardened revolves on the turntable 420 with the turntable 420 and rotates around its own axis to ensure that the cylindrical surface of the workpiece to be hardened is evenly infiltrated with nitrogen ions.

[0131] 7. In order to ensure that the temperature of the parts will not be too high when the carbon ions and nitrogen ions strongly bombard the surface of the hardened parts, after each carbon ion and nitrogen ion infiltration treatment for 5 minutes, the cooling is suspended for 60 minutes and the cycle is repeated 10 times.

[0132] 8. After 10 carbon ion and nitrogen ion penetrations are completed, the gas ion source 460, the solid ion source 470, the bias power supply and the argon gas introduced into the vacuum chamber 400 are turned off. The turntable 420 is turned off, and after the hardened part in the vacuum chamber 400 is cooled to below 60° C., air or nitrogen is filled into the vacuum chamber 400, and the hardened part is taken out.

[0133] See also Figure 1 and Figure 2 In some embodiments, the hydrodynamic sliding bearing assembled after hardening using the aforementioned hardening method includes a core shaft 100 and a sleeve 200, wherein the sleeve 200 is sleeved on the outside of the core shaft 100, and there is a gap 300 between the core shaft 100 and the sleeve 200, and the gap 300 is filled with a hydrodynamic fluid. The outer circumference of the core shaft 100 and / or the inner circumference of the sleeve 200 are configured to infiltrate non-metallic ions under a vacuum environment to form a surface hardened layer, wherein the non-metallic ions include carbon ions and / or nitrogen ions.

[0134] In some embodiments, the outer circumferential surface of the core shaft 100 is provided with a spiral groove 110 , and the groove wall of the spiral groove 110 is configured to infiltrate non-metallic ions under a vacuum environment to form a surface hardening layer, and the non-metallic ions include carbon ions and / or nitrogen ions.

[0135] Specifically, when hardening is performed by the aforementioned hardening method, in addition to hardening the outer circumference of the core shaft 100 and / or the inner circumference of the sleeve 200, the groove wall of the spiral groove 110 is also hardened, so that its surface hardness and strength are also higher.

[0136] In some embodiments, the hydrodynamic fluid is typically liquid metal.

[0137] Furthermore, in some embodiments, the material of the dynamic pressure fluid is gallium, mercury or gallium indium tin alloy. The materials of the core shaft 100 and the sleeve 200 are the same or different materials with high hardness such as molybdenum, cemented carbide T15, cemented carbide GT35 or M62.

[0138] In some embodiments, the X-ray tube comprises the hydrodynamic sliding bearing of any one of the above embodiments.

[0139] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for hardening a hydrodynamic sliding bearing, the hydrodynamic sliding bearing comprising a core shaft (100) and a sleeve (200) sleeved on the outside of the core shaft (100), a gap (300) being provided between the core shaft (100) and the sleeve (200), the gap (300) being filled with a hydrodynamic fluid, characterized in that: The hardening method of the dynamic pressure sliding bearing comprises: Placing a workpiece to be hardened in a vacuum chamber (410), wherein the workpiece to be hardened includes at least one of the mandrel (100) and the sleeve (200); Non-metallic ions are emitted through an ion source, and are accelerated under the action of an accelerating electric field to bombard a surface to be hardened of the part to be hardened, wherein the surface to be hardened includes an outer peripheral surface of the core shaft (100) and / or an inner peripheral surface of the sleeve (200), and the non-metallic ions include carbon ions and / or nitrogen ions.

2. The hardening method of a dynamic pressure sliding bearing according to claim 1, characterized in that: The ion source of the nitrogen ions is a gas ion source (460), and the ion source of the carbon ions is a solid ion source (470).

3. The hardening method of a dynamic pressure sliding bearing according to claim 2, characterized in that: The method of infiltrating the nitrogen ions and the carbon ions into the surface to be hardened is: The solid ion source (470) is placed in the vacuum chamber (410), nitrogen gas or nitrogen-argon mixed gas is introduced into the vacuum chamber (410), so that the pressure in the vacuum chamber (410) reaches a preset stable value, the nitrogen ions are ionized by the gas ion source (460), and the carbon ions are ionized by the solid ion source (470), and the nitrogen ions and the carbon ions are accelerated to bombard the surface to be hardened.

4. The method for hardening a dynamic pressure sliding bearing according to any one of claims 1 to 3, characterized in that: Before placing the workpiece to be hardened in the vacuum chamber (410), the method further comprises: The dynamic pressure sliding bearing is finely processed, and the fine processing method includes: forming a spiral groove (110) on the outer peripheral surface of the core shaft (100), and the spiral groove (110) is connected to the gap (300) for passing the dynamic pressure fluid.

5. The method for hardening a dynamic pressure sliding bearing according to claim 4, characterized in that: When the non-metallic ions are emitted by the ion source to bombard the surface to be hardened, the temperature of the part to be hardened is controlled to be lower than its tempering temperature.

6. The hardening method of a dynamic pressure sliding bearing according to claim 5, characterized in that: The method of controlling the temperature of the hardened part includes: Adjust the ion flow density of the non-metallic ions, and / or adjust the duration of the non-metallic ions bombarding the surface to be hardened, and / or adjust the internal voltage of the ion source, and / or adjust the voltage of the power supply used to form the accelerating electric field.

7. A hydrodynamic sliding bearing, characterized in that: The dynamic pressure sliding bearing comprises: Mandrel (100); A sleeve (200) is sleeved on the outside of the core shaft (100), and a gap (300) is provided between the core shaft (100) and the sleeve (200), and the gap (300) is filled with a dynamic pressure fluid; The outer circumferential surface of the core shaft (100) and / or the inner circumferential surface of the sleeve (200) are configured to be infiltrated with non-metallic ions under a vacuum environment to form a surface hardening layer, wherein the non-metallic ions include carbon ions and / or nitrogen ions.

8. The dynamic pressure sliding bearing according to claim 7, characterized in that: The outer peripheral surface of the core shaft (100) is provided with a spiral groove (110), and the groove wall of the spiral groove (110) is configured to infiltrate non-metallic ions in a vacuum environment to form a surface hardening layer, and the non-metallic ions include carbon ions and / or nitrogen ions.

9. The dynamic pressure sliding bearing according to claim 7, characterized in that: The material of the dynamic pressure fluid is gallium, mercury or gallium-indium-tin alloy.

10. An X-ray tube, characterized in that A hydrodynamic sliding bearing comprising the hydrodynamic sliding bearing according to any one of claims 7 to 9.

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