Vacuum brazing PDC thrust bearing manufacturing device and method

Abstract

The invention provides a vacuum brazing PDC thrust bearing manufacturing device and method, and relates to the technical field of bearing manufacturing, the device comprises an upper mold, a lower mold, a lower mold, a plurality of upper limiting plates and a plurality of lower limiting plates, the upper mold comprises an upper base and a plurality of arc-shaped upper limiting plates, and the lower surface of the upper base is located in a first circumference and provided with a plurality of grooves; the lower die comprises a lower base and a plurality of arc-shaped lower limiting plates; the upper mold is arranged on the lower mold, the upper mold and the lower mold are detachably connected through the fasteners, all the upper limiting plates and all the lower limiting plates are formed in a one-to-one embedded mode, all the grooves are aligned with blind holes in the upper portion of the bearing base one by one, and therefore the upper ends of the PDC clad sheets to be welded are embedded into the grooves, and the lower ends of the PDC clad sheets to be welded are inserted into the blind holes. The method has the beneficial effects that the PDC clad sheet and the molten brazing filler metal are fully infiltrated, and the welding strength is guaranteed; the positioning accuracy of the PDC clad sheet can be guaranteed, and the problems that the PDC clad sheet topples over and is poor in flatness when the PDC clad sheet is brazed are effectively solved.

Description

Technical Field

[0001] The invention relates to the technical field of bearing manufacturing, and in particular to a vacuum brazing PDC thrust bearing manufacturing device and method. Background Art

[0002] PDC thrust bearings are often used in the transmission shaft of screw drilling tools. Compared with traditional bearings, the PDC composite sheets embedded on their surfaces have high hardness and low friction coefficient, which greatly increases the impact resistance and wear resistance of the bearings, and can still maintain good performance in harsh underground environments. PDC thrust bearings are commonly manufactured by brazing methods. There are many process methods for brazing, but the fundamental principle is to use some physical and chemical methods. Heat a brazing material with a lower melting point than the parent metal until the brazing material melts but the weld does not melt, so that the parent material is wetted by the liquid brazing material. Fill the gap between the weld and the parent material and diffuse with each other to achieve the connection between the weld and the parent material. When the PDC composite sheet of the current PDC thrust bearing is brazed, the melting of the brazing material arranged between the PDC thrust bearing and the PDC composite sheet will cause the position of the PDC composite sheet to change or even tilt. On the one hand, it will cause insufficient wetting of the brazing material and the PDC thrust bearing during brazing, affecting the welding strength; on the other hand, the position of the PDC composite sheet after welding cannot be guaranteed, affecting the flatness of the working surface of the PDC thrust bearing after welding. Summary of the invention

[0003] In view of this, in order to solve the above-mentioned problems existing in the brazing of PDC composite sheets of a PDC thrust bearing, an embodiment of the present invention provides a vacuum brazing PDC thrust bearing manufacturing device and method.

[0004] An embodiment of the present invention provides a vacuum brazing PDC thrust bearing manufacturing device, comprising:

[0005] An upper mold, comprising an upper base and a plurality of arc-shaped upper limit plates, each of which is arranged at intervals on a first circumference on the lower surface of the upper base, and a plurality of grooves are arranged on the lower surface of the upper base within the first circumference;

[0006] A lower mold, comprising a lower base and a plurality of arc-shaped lower limit plates, each of which is arranged at intervals on a second circumference on the upper surface of the lower base, and the inner diameters of the first circumference and the second circumference are both the same as the outer diameter of the bearing base;

[0007] And a fastener, the upper mold is placed on the lower mold, the fastener connects the upper mold and the lower mold detachably, so that all upper limit plates and all lower limit plates are embedded one by one to form a cylindrical space that can accommodate the bearing base, and each of the grooves is aligned one by one with the blind hole on the upper part of the bearing base, so that the upper end of the PDC composite sheet to be welded is embedded in the groove and the lower end is inserted into the blind hole.

[0008] Furthermore, the groove is a cylindrical groove, the diameter of the groove is the same as the diameter of the PDC composite sheet to be welded, and the diameter of the groove is smaller than the diameter of the blind hole.

[0009] Furthermore, the number of the upper limit plates and the lower limit plates is the same, and the upper limit plates are arranged on the upper base at equal intervals, and the lower limit plates are arranged on the lower base at equal intervals.

[0010] Further, the number of the upper limit plate and the number of the lower limit plate are both set to two, and the central angles corresponding to the upper limit plate and the lower limit plate are both 90°.

[0011] Furthermore, the heights of the upper limit plate and the lower limit plate are both the same as the height of the bearing base.

[0012] Furthermore, the upper mold also includes an upper limit cone, which is arranged on the lower surface of the upper base, and each of the grooves surrounds the upper limit cone. The lower mold also includes a lower limit cone, which is arranged on the lower surface of the lower base. The upper limit cone and the lower limit cone can be respectively embedded in the upper end and lower end of the inner hole of the bearing base.

[0013] Furthermore, the sum of the heights of the upper limit truncated cone and the lower limit truncated cone is not higher than the height of the bearing base.

[0014] In addition, an embodiment of the present invention further provides a method for manufacturing a vacuum brazed PDC thrust bearing, using the above-mentioned vacuum brazed PDC thrust bearing manufacturing device, and further comprising the following steps:

[0015] S1. Place a predetermined weight of solder in each blind hole on the bearing base to be welded;

[0016] S2, placing the bearing base on the lower base, making the outer wall of the bearing base fit with the inner surface of each lower limit plate, placing a PDC composite sheet on the solder in each blind hole, the PDC composite sheet and the blind hole have a gap fit and the upper end extends out of the upper end of the blind hole;

[0017] S3, cover the upper base on the lower base, so that all upper limit plates and all lower limit plates are embedded one by one, the inner surface of each upper limit plate is in contact with the outer wall of the bearing base, and the upper end of each PDC composite sheet is fixedly embedded in one of the grooves;

[0018] S4, fastening the upper base and the lower base together by fasteners, and sending the whole into a vacuum brazing furnace, where the vacuum brazing furnace is heated to melt the brazing material;

[0019] S5, the brazing filler metal is cooled to weld the PDC composite sheet and the bearing base.

[0020] Furthermore, the PDC composite sheet is a cylindrical graphite material, and the solder is a silver-based solder.

[0021] Furthermore, in step S4, the vacuum brazing is heated to 700° C. and kept warm for 30 to 60 minutes, and the heating rate during heating is 5 to 10° C. / min.

[0022] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention are:

[0023] The present invention discloses a vacuum brazing PDC thrust bearing manufacturing device and method, which limits the bearing base through the cooperation of an upper limit plate and a lower limit plate, and at the same time, by providing a groove on the lower surface of the upper base, the lower end of the PDC composite sheet to be welded is placed in a blind hole on the bearing base, and the upper end is fixedly embedded in the groove on the upper base. After the brazing material in the blind hole on the bearing base is melted, the position of the PDC composite sheet is not changed, so that the PDC composite sheet and the melted brazing material are fully infiltrated to ensure the welding strength; and because the upper end of the PDC composite sheet is fixed on the upper base when the brazing material is melted, the positioning accuracy of the PDC composite sheet can be guaranteed, and the problem of PDC composite sheet tipping and poor flatness when brazing the PDC composite sheet is effectively solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the bearing base;

[0025] Figure 2 is a schematic diagram of the lower mold;

[0026] Figure 3 is a schematic diagram of the upper mold;

[0027] Figure 4 It is a partial cross-sectional view of the blind hole in the bearing base filled with brazing material;

[0028] Figure 5 It is a partial cross-sectional view of the groove on the base where the PDC composite sheet is filled;

[0029] Figure 6 The embodiment of the present invention provides a schematic diagram of a vacuum brazing PDC thrust bearing manufacturing device after the brazing material and PDC composite sheet are filled.

[0030] In the figure: 1. bearing base; 101. blind hole; 2. lower mold; 201. lower base; 202. lower limit cone; 203. lower limit plate; 3. upper mold; 301. upper base; 302. upper limit cone; 303. upper limit plate; 304. groove; 4. solder; 5. PDC composite sheet; 6. positioning pin. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention clearer, the following will further describe the embodiments of the present invention in conjunction with the accompanying drawings. The following is a preferred embodiment of the present invention, which is intended to provide a basic understanding of the present invention, but is not intended to confirm the key or decisive elements of the present invention or to limit the scope of protection.

[0032] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0033] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0034] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in the subsequent drawings. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0035] It should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral 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, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Please refer to Figure 1-6 The embodiment of the present invention provides a vacuum brazing PDC thrust bearing manufacturing device, which welds a PDC composite sheet 5 to a bearing base 1, and mainly includes an upper mold 3, a lower mold 2 and fasteners.

[0037] The bearing base 1 is generally annular, and the upper surface of the bearing base 1 is provided with a plurality of blind holes 101 for installing the PDC composite sheet 5. Figure 1 As shown, in this embodiment, the bearing base 1 is made of 42CrMo steel, and the number of the blind holes 101 is set to 23. It can be understood that the material of the bearing base 1 and the number of the blind holes 101 can be flexibly set according to the specifications and models of the PDC thrust bearing.

[0038] The upper mold 3 includes an upper base 301 and a plurality of arc-shaped upper limit plates 303 , each of which is arranged at intervals on a first circumference on the lower surface of the upper base 301 , and a plurality of grooves 304 are arranged on the lower surface of the upper base 301 within the first circumference.

[0039] The lower mold 2 includes a lower base 201 and a plurality of arc-shaped lower limit plates 203 , each of which is arranged at intervals on a second circumference on the upper surface of the lower base 201 , and the inner diameters of the first circumference and the second circumference are the same as the outer diameter of the bearing base 1 .

[0040] Specifically, the upper mold 3 and the lower mold 2 are both made of graphite material. The upper base 301 and the lower base 201 are both circular plates, the first circumference is coaxially arranged with the upper base 301 , and the second circumference is coaxially arranged with the lower base 201 .

[0041] The upper limit plate 303 and the lower limit plate 203 are simultaneously fitted with the outer wall of the bearing base 1, thereby radially limiting the bearing base 1. The number of the upper limit plates 303 and the lower limit plates 203 is generally the same, and the upper limit plates 303 are arranged at equal intervals on the upper base 301, and the lower limit plates 203 are arranged at equal intervals on the lower base 201. In this embodiment, the number of the upper limit plates 303 and the lower limit plates 203 are both set to two, and the corresponding central angles of the upper limit plates 303 and the lower limit plates 203 are both 90°.

[0042] Furthermore, the heights of the upper limit plate 303 and the lower limit plate 203 are the same as the height of the bearing base 1 , so that the upper limit plate 303 and the lower limit plate 203 can just abut against the upper and lower ends of the bearing base 1 to axially limit the bearing base 1 .

[0043] The number of the grooves 304 is the same as the number of the blind holes 101 on the bearing base 1, and the positions correspond one to one. As described in this embodiment, the number of the grooves 304 is also 23.

[0044] The lower end of the PDC composite sheet 5 to be welded is placed in the blind hole 101, and the upper end is inserted into and fixed to the groove 304. As in this embodiment, the lower end of the PDC composite sheet 5 is clearance-fitted with the blind hole 101, and the upper end is interference-fitted with the groove 304.

[0045] The PDC composite sheet 5 is generally cylindrical, so the groove 304 is a cylindrical groove. The diameter of the groove 304 is the same as the diameter of the PDC composite sheet 5 to be welded, and the diameter of the groove 304 is smaller than the diameter of the blind hole 101 .

[0046] The upper mold 3 is placed on the lower mold 2, and the fasteners detachably connect the upper mold 3 and the lower mold 2, so that all upper limit plates 303 and all lower limit plates 203 are embedded one by one to form a cylindrical space that can accommodate the bearing base 1, and each of the grooves 304 is aligned one by one with the blind hole 101 on the upper part of the bearing base 1, so that the upper end of the PDC composite sheet 5 to be welded is embedded in the groove 304 and the lower end is inserted into the blind hole 101.

[0047] The fastener can be flexibly arranged according to actual needs, and it is sufficient to detachably connect the upper mold 3 and the lower mold 2. In this embodiment, the fastener is a positioning pin 6, and a plurality of positioning pins 6 can be provided. The plurality of positioning pins 6 fasten the edge of the upper base 301 to the edge of the lower base 201.

[0048] In some embodiments, the upper mold 3 further includes an upper limit cone 302, which is disposed on the lower surface of the upper base 301, and each of the grooves 304 surrounds the upper limit cone 302, and the lower mold 2 further includes a lower limit cone 202, which is disposed on the lower surface of the lower base 201. When the bearing base 1 is placed between the upper limit plate 303 and the lower limit plate 203, the upper limit cone 302 and the lower limit cone 202 can be respectively embedded in the upper and lower ends of the inner hole of the bearing base 1 to better limit the radial position of the bearing base 1. Generally, the sum of the heights of the upper limit cone 302 and the lower limit cone 202 is not higher than the height of the bearing base 1.

[0049] In addition, an embodiment of the present invention further provides a method for manufacturing a vacuum brazed PDC thrust bearing, using the above-mentioned vacuum brazed PDC thrust bearing manufacturing device, and further comprising the following steps:

[0050] S1, such as Figure 4 As shown, a predetermined weight of solder 4 is placed in each blind hole 101 on the bearing base 1 to be welded.

[0051] Before brazing, the upper mold 3, the lower mold 2, the brazing material 4 and the PDC composite sheet 5 are firstly cleaned on the surface.

[0052] The solder 4 is a silver-based solder, specifically BAg612, whose composition is BAg40CuZnCdNi, wherein the mass fraction of silver is 40%. The melting temperature is between 630 and 680°C, and it has good wettability to many metals, good fluidity and filling properties.

[0053] The silver-based solder is cut into discs with a thickness of about 0.1 mm, adapted to the diameter of the blind hole 101 of the bearing base 1, so that it can fall into the blind hole 101. The cut and weighed solders 4 are placed one by one into the blind holes 101 of the bearing base 1 and leveled to ensure that the amount of solder 4 placed in each blind hole 101 is the same.

[0054] S2. Place the bearing base 1 on the lower base 201 so that the outer wall of the bearing base 1 fits with the inner surface of each lower limit plate 203, and place a PDC composite sheet 5 on the solder 4 in each blind hole 101. The PDC composite sheet 5 is gap-fitted with the blind hole 101 and the upper end extends out of the upper end of the blind hole 101.

[0055] When placing the bearing base 1, the blind hole 101 is facing upward, the outer wall of the bearing base 1 is fitted with the inner surface of the lower limit plate 203, and the inner hole is sleeved on the lower limit truncated cone 202. Then, the cylindrical PDC composite sheet 5 is vertically inserted into the blind hole 101 of the bearing base 1, and the lower end of the PDC composite sheet 5 is gap-fitted with the blind hole 101.

[0056] S3, such as Figure 5 and Figure 6 As shown, the upper base 301 is covered on the lower base 201, so that all upper limit plates 303 and all lower limit plates 203 are embedded one by one, the inner surface of each upper limit plate 303 is in contact with the outer wall of the bearing base 1, and the upper end of each PDC composite sheet 5 is fixedly embedded in a groove 304.

[0057] The upper limit plates 303 on the upper base 301 and the lower limit plates 203 on the lower base 201 are inserted staggered, and the grooves 304 are aligned with the upper ends of the PDC composite sheets 5 one by one. The upper base 301 is tapped lightly with a rubber hammer to complete the engagement of all the upper limit plates 303 and all the lower limit plates 203, and to embed the upper ends of the PDC composite sheets 5 into the grooves 304 so that the PDC composite sheets 5 are fixed.

[0058] S4. The upper base 301 and the lower base 201 are fastened together by fasteners, and the whole is sent into a vacuum brazing furnace, and the vacuum brazing furnace is heated to melt the brazing material 4.

[0059] Then the assembled vacuum brazing PDC thrust bearing manufacturing device is put into the vacuum brazing furnace as a whole. In this example, the ZKR-2FH vacuum brazing furnace is used. First, the furnace is evacuated using low vacuum operation. When the vacuum reaches the upper limit of the low vacuum circuit, high vacuum operation is started. When the vacuum in the furnace reaches 1×10- 2Heating starts at 0.0400 Pa, and the initial heating rate should not be too fast, and 5-10℃ / min is recommended. In order to ensure that the internal and external temperatures of the component are basically consistent when the solder 4 melts, so that the capillary effect can be well exerted, the heating rate should not be too fast when heated to 50-100℃ below the solidus temperature of the solder 4 (i.e. 530℃-580℃), and the heating rate is recommended not to exceed 5℃ / min. In order to avoid the segregation of the solder 4 and increase the liquidus temperature, faster heating is required within the melting temperature range of the solder 4 (i.e. 630-680℃), and the heating rate is recommended to be above 15℃ / min. After heating to 700℃, it needs to be kept warm for 0.5-1h.

[0060] S5 , the brazing material 4 is cooled to weld the PDC composite sheet 5 and the bearing base 1 .

[0061] Then turn off the heating button of the vacuum brazing furnace and allow the workpiece furnace to cool to room temperature (25°C).

[0062] It should be noted that during the process of heating, heat preservation and cooling to room temperature, the furnace needs to maintain a high vacuum environment. After cooling to room temperature, start exhausting, take out the bearing base 1 workpiece, and remove the mold.

[0063] In this article, the directional words such as front, back, top, and bottom involved are defined by the positions of the parts in the drawings and the positions of the parts relative to each other, just for the sake of clarity and convenience in expressing the technical solution. It should be understood that they are relative concepts and can change accordingly according to different ways of use and placement, and the use of the directional words should not limit the scope of protection claimed in this application.

[0064] In the absence of conflict, the above embodiments and features in the embodiments may be combined with each other. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A vacuum brazing PDC thrust bearing manufacturing device, characterized in that: include: An upper mold, comprising an upper base and a plurality of arc-shaped upper limit plates, each of which is arranged at intervals on a first circumference on the lower surface of the upper base, and a plurality of grooves are arranged on the lower surface of the upper base within the first circumference; A lower mold, comprising a lower base and a plurality of arc-shaped lower limit plates, each of which is arranged at intervals on a second circumference on the upper surface of the lower base, and the inner diameters of the first circumference and the second circumference are both the same as the outer diameter of the bearing base; And a fastener, the upper mold is placed on the lower mold, the fastener connects the upper mold and the lower mold detachably, so that all upper limit plates and all lower limit plates are embedded one by one to form a cylindrical space that can accommodate the bearing base, and each of the grooves is aligned one by one with the blind hole on the upper part of the bearing base, so that the upper end of the PDC composite sheet to be welded is embedded in the groove and the lower end is inserted into the blind hole.

2. A vacuum brazing PDC thrust bearing manufacturing device as claimed in claim 1, characterized in that: The groove is a cylindrical groove, the diameter of the groove is the same as the diameter of the PDC composite sheet to be welded, and the diameter of the groove is smaller than the diameter of the blind hole.

3. A vacuum brazing PDC thrust bearing manufacturing device as claimed in claim 1, characterized in that: The number of the upper limit plates and the lower limit plates is the same, and the upper limit plates are arranged on the upper base at equal intervals, and the lower limit plates are arranged on the lower base at equal intervals.

4. A vacuum brazing PDC thrust bearing manufacturing device as claimed in claim 3, characterized in that: The number of the upper limit plate and the number of the lower limit plate are both set to two, and the central angles corresponding to the upper limit plate and the lower limit plate are both 90°.

5. A vacuum brazing PDC thrust bearing manufacturing device as claimed in claim 1, characterized in that: The heights of the upper limit plate and the lower limit plate are both the same as the height of the bearing base.

6. A vacuum brazing PDC thrust bearing manufacturing device as claimed in claim 1, characterized in that: The upper mold also includes an upper limit cone, which is arranged on the lower surface of the upper base, and each of the grooves surrounds the upper limit cone. The lower mold also includes a lower limit cone, which is arranged on the lower surface of the lower base. The upper limit cone and the lower limit cone can be respectively embedded in the upper end and lower end of the inner hole of the bearing base.

7. A vacuum brazing PDC thrust bearing manufacturing device as claimed in claim 6, characterized in that: The sum of the heights of the upper limit truncated cone and the lower limit truncated cone is not higher than the height of the bearing base.

8. A method for manufacturing a vacuum brazed PDC thrust bearing, characterized in that: A vacuum brazing PDC thrust bearing manufacturing device according to any one of claims 1 to 7 is used, and further comprising the following steps: S1. Place a predetermined weight of solder in each blind hole on the bearing base to be welded; S2, placing the bearing base on the lower base, making the outer wall of the bearing base fit with the inner surface of each lower limit plate, placing a PDC composite sheet on the solder in each blind hole, the PDC composite sheet and the blind hole have a gap fit and the upper end extends out of the upper end of the blind hole; S3, cover the upper base on the lower base, so that all upper limit plates and all lower limit plates are embedded one by one, the inner surface of each upper limit plate is in contact with the outer wall of the bearing base, and the upper end of each PDC composite sheet is fixedly embedded in one of the grooves; S4, fastening the upper base and the lower base together by fasteners, and sending the whole into a vacuum brazing furnace, where the vacuum brazing furnace is heated to melt the brazing material; S5, the brazing filler metal is cooled to weld the PDC composite sheet and the bearing base.

9. A method for manufacturing a vacuum brazed PDC thrust bearing according to claim 8, characterized in that: The PDC composite sheet is a cylindrical graphite material, and the solder is a silver-based solder.

10. A method for manufacturing a vacuum brazed PDC thrust bearing according to claim 8, characterized in that: In step S4, the vacuum brazing is heated to 700° C. and kept warm for 30 to 60 minutes, and the heating rate during heating is 5 to 10° C. / min.

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