A vacuum brazing pdc thrust bearing manufacturing apparatus and method

Abstract

The application provides a vacuum brazing PDC thrust bearing manufacturing device and method, relates to a bearing manufacturing technical field, and comprises the following: an upper die which comprises an upper base and a plurality of arc-shaped upper limiting plates, a plurality of grooves are arranged on the lower surface of the upper base and located in a first circle; a lower die which comprises a lower base and a plurality of arc-shaped lower limiting plates; and a fastener, the upper die is placed on the lower die, the fastener is used for detachably connecting the upper die and the lower die, all the upper limiting plates and all the lower limiting plates are embedded in a one-to-one mode to form, each groove is aligned with a blind hole on the upper part of the bearing base in a one-to-one mode, so that the upper end of the PDC composite sheet to be welded is embedded into the groove and the lower end is inserted into the blind hole. The application has the beneficial effects that the PDC composite sheet is fully infiltrated with the melted filler material, the welding strength is guaranteed, the positioning accuracy of the PDC composite sheet is guaranteed, and the problems of PDC composite sheet tilting and poor flatness during brazing of the PDC composite sheet are effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearing manufacturing, and particularly relates to a vacuum brazing PDC thrust bearing manufacturing device and method. BACKGROUND

[0002] The PDC thrust bearing is often used in the transmission shaft part of the screw drill, and compared with the traditional bearing, the PDC thrust bearing has high hardness and low friction coefficient of the PDC composite sheet embedded on the surface, greatly increases the impact resistance and wear resistance of the bearing, and can still maintain good use performance in the harsh environment in the well. The brazing method is often used in the manufacturing of the PDC thrust bearing, and there are many brazing process methods, but the basic principle is to use some physical and chemical methods. The brazing filler metal with a lower melting point than the base metal is heated until the brazing filler metal is melted but the welding part is not melted, so that the base metal is wetted by the liquid brazing filler metal. The gap between the welding part and the base metal is filled and diffused, so as to realize the connection between the welding part and the base metal. When the PDC composite sheet of the PDC thrust bearing is brazed, the melting of the brazing filler metal arranged between the PDC thrust bearing and the PDC composite sheet will change the position of the PDC composite sheet or even tilt the PDC composite sheet. On the one hand, the problem of insufficient wetting of the brazing filler metal and the PDC thrust bearing during brazing will affect the welding strength; on the other hand, the position of the PDC composite sheet after welding cannot be guaranteed, which will affect the flatness of the working surface of the PDC thrust bearing after welding. SUMMARY

[0003] Therefore, in order to solve the above problems existing in the brazing of the PDC composite sheet of the PDC thrust bearing, the embodiments of the present application provide a vacuum brazing PDC thrust bearing manufacturing device and method.

[0004] The embodiments of the present application provide a vacuum brazing PDC thrust bearing manufacturing device, which comprises:

[0005] An upper die comprises an upper base and a plurality of arc-shaped upper limiting plates, each of the upper limiting plates is arranged on a first circle on the lower surface of the upper base in a spaced manner, and a plurality of grooves are arranged on the lower surface of the upper base in the first circle;

[0006] A lower die comprises a lower base and a plurality of arc-shaped lower limiting plates, each of the lower limiting plates is arranged on a second circle on the upper surface of the lower base in a spaced manner, and the inner diameters of the first circle and the second circle are the same as the outer diameter of the bearing base;

[0007] and a fastener, the upper die is arranged on the lower die, the fastener detachably connects the upper die and the lower die, all the upper limiting plates and all the lower limiting plates are embedded one by one to form a cylindrical space capable of accommodating the bearing base, each of the grooves is aligned 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] Further, the groove is a cylindrical groove, the diameter of the groove is the same as the diameter of the PDC compact to be welded, and the diameter of the groove is smaller than the diameter of the blind hole.

[0009] Further, the number of the upper limit plates and the lower limit plates is the same, 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 plates and the lower limit plates is two, and the central angle corresponding to the upper limit plate and the lower limit plate is 90°.

[0011] Further, the height of the upper limit plate and the lower limit plate is the same as the height of the bearing base.

[0012] Further, the upper die further comprises an upper limit circular table, the upper limit circular table is arranged on the lower surface of the upper base, and each groove surrounds the upper limit circular table, the lower die further comprises a lower limit circular table, the lower limit circular table is arranged on the lower surface of the lower base, and the upper limit circular table and the lower limit circular table can be respectively embedded into the upper end and the lower end of the inner hole of the bearing base.

[0013] Further, the sum of the height of the upper limit circular table and the lower limit circular table is not higher than the height of the bearing base.

[0014] In addition, the embodiment of the present application also provides a vacuum brazing PDC thrust bearing manufacturing method, which uses the vacuum brazing PDC thrust bearing manufacturing device and further comprises the following steps.

[0015] S1, placing a predetermined weight of filler metal in each blind hole on the bearing base to be welded;

[0016] S2, placing the bearing base on the lower base, so that the outer wall of the bearing base is attached to the inner surface of each lower limit plate, and placing a PDC compact on the filler metal in each blind hole, the PDC compact is in clearance fit with the blind hole and the upper end of the PDC compact extends out of the upper end of the blind hole;

[0017] S3, covering the upper base on the lower base, so that all the upper limit plates and all the lower limit plates are embedded one by one, the inner surface of each upper limit plate is attached to the outer wall of the bearing base, and the upper end of each PDC compact is fixedly embedded into a groove;

[0018] S4, fastening and connecting the upper base and the lower base through fasteners, and sending the whole into a vacuum brazing furnace, and heating the vacuum brazing furnace to melt the filler metal;

[0019] S5, the solder cools to weld the PDC composite sheet and the bearing base.

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

[0021] Further, in the step S4, the vacuum brazing is heated to 700 DEG C and kept for 30-60 min, and the heating rate is 5-10 DEG C / min.

[0022] The technical scheme provided by the embodiment of the application has the beneficial effects that:

[0023] The vacuum brazing PDC thrust bearing manufacturing device and method provided by the application limits the bearing base through the upper and lower limiting plates, and the lower end of the PDC composite sheet to be welded is placed in the blind hole on the bearing base, and the upper end is fixedly embedded in the groove on the upper base, so that the position of the PDC composite sheet is not changed after the solder in the blind hole on the bearing base is melted, the PDC composite sheet is fully infiltrated with the melted solder, and the welding strength is ensured; and since the upper end of the PDC composite sheet is fixed on the upper base when the solder is melted, the positioning accuracy of the PDC composite sheet can be ensured, and the problems of PDC composite sheet tilting and poor flatness during brazing of the PDC composite sheet are effectively solved. BRIEF DESCRIPTION OF DRAWINGS

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

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

[0026] Figure 3 is a schematic view of an upper mold;

[0027] Figure 4 is a partial sectional view of the solder filling the blind hole in the bearing base;

[0028] Figure 5 is a partial sectional view of the PDC composite sheet filling the groove on the upper base;

[0029] Figure 6 is a schematic view of the vacuum brazing PDC thrust bearing manufacturing device provided by the embodiment of the application after the solder and the PDC composite sheet are filled.

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

[0031] The objectives, technical solutions and advantages of the present application will become more apparent from the following description of the embodiments of the present application. The following description is of a preferred embodiment of the present application, and is not intended to limit the scope of the application.

[0032] In all examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0033] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail herein, but should be considered as part of the specification, where appropriate.

[0034] It should be noted that like reference numerals and letters refer to like items in the several views of the drawings, and as such, further discussion of such items is not necessary in the subsequent views. It should also be understood that the various embodiments of the present application will be described herein in terms of specific configurations and arrangements of elements, it being understood that these are provided for purposes of exemplary description and illustration, and are not intended to be limiting of the application.

[0035] It should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through intermediate medium, can be internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] Please refer to Figures 1-6 The embodiment of the present application provides a kind of vacuum brazing PDC thrust bearing manufacturing device, PDC composite sheet 5 is welded on bearing base 1, mainly including upper die 3, lower die 2 and fastener.

[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 mounting the PDC composite sheet 5.As shown in Figure 1 In the embodiment, the material of 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 die 3 comprises an upper base 301 and a plurality of arc-shaped upper limiting plates 303, each of which is arranged 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 die 2 comprises a lower base 201 and a plurality of arc-shaped lower limiting plates 203, each of which is arranged 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 die 3 and the lower die 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 limiting plate 303 and the lower limiting 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 limiting plate 303 and the lower limiting plate 203 is generally the same, and the upper limiting plate 303 is arranged on the upper base 301 at equal intervals, and the lower limiting plate 203 is arranged on the lower base 201 at equal intervals. In this embodiment, the number of the upper limiting plate 303 and the lower limiting plate 203 is two, and the central angle corresponding to the upper limiting plate 303 and the lower limiting plate 203 is 90°.

[0042] And the height of the upper limiting plate 303 and the lower limiting plate 203 is the same as the height of the bearing base 1, so that the upper limiting plate 303 and the lower limiting plate 203 can just abut against the upper and lower ends of the bearing base 1, thereby axially limiting 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 are one-to-one corresponding. 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 arranged in the blind hole 101, and the upper end is inserted into the groove 304 and fixed with the groove 304. In this embodiment, the lower end of the PDC composite sheet 5 is clearance fit with the blind hole 101, and the upper end is interference fit 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 the upper limiting plates 303 and all the lower limiting plates 203 are embedded one by one to form a cylindrical space capable of accommodating the bearing base 1, each of the grooves 304 is aligned 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 fasteners can be flexibly arranged according to actual needs, as long as the upper mold 3 and the lower mold 2 can be detachably connected. In the embodiment, the fastener is a positioning pin 6, and a plurality of positioning pins 6 can be arranged to fasten and connect the edges of the upper base 301 and the edges of the lower base 201.

[0048] In some embodiments, the upper mold 3 further comprises an upper limiting circular table 302 arranged on the lower surface of the upper base 301, and each of the grooves 304 surrounds the upper limiting circular table 302. The lower mold 2 further comprises a lower limiting circular table 202 arranged on the lower surface of the lower base 201. When the bearing base 1 is placed between the upper limiting plate 303 and the lower limiting plate 203, the upper limiting circular table 302 and the lower limiting circular table 202 can be embedded into the upper end and the lower end of the inner hole of the bearing base 1, respectively, to better limit the bearing base 1 in the radial direction. Generally, the sum of the heights of the upper limiting circular table 302 and the lower limiting circular table 202 is not higher than the height of the bearing base 1.

[0049] In addition, the embodiment of the present application also provides a vacuum brazing PDC thrust bearing manufacturing method, which uses the vacuum brazing PDC thrust bearing manufacturing device and further comprises the following steps:

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

[0051] Before brazing, the upper mold 3, the lower mold 2, the brazing filler metal 4 and the PDC composite sheet 5 are first cleaned.

[0052] The brazing filler metal 4 is a silver-based brazing filler metal, and specifically can be a silver-based brazing filler metal of BAg612, which has a composition of BAg40CuZnCdNi, and the mass fraction of silver is 40%. The melting temperature is between 630-680℃, and has good wettability, good flowability and good caulking property for many metals.

[0053] ​Silver-based filler material is cut into a round shape with a thickness of about 0.1mm, which is suitable for 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 filler material 4 is placed into the blind hole 101 of the bearing base 1 one by one and leveled, ensuring that the amount of filler material 4 placed in each blind hole 101 is the same.

[0054] S2, the bearing base 1 is placed on the lower base 201, the outer wall of the bearing base 1 is attached to the inner surface of each lower limiting plate 203, and the PDC composite sheet 5 is placed on the filler material 4 in each blind hole 101, the PDC composite sheet 5 is in clearance fit 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 upward, the outer wall of the bearing base 1 is attached to the inner surface of the lower limiting plate 203, and the inner hole is sleeved on the lower limiting circular table 202. Then the cylindrical PDC composite sheet 5 is vertically inserted into the blind hole 101 of the bearing base 1, at this time the lower end of the PDC composite sheet 5 is in clearance fit with the blind hole 101.

[0056] S3, as shown in Figure 5 and Figure 6 The upper base 301 is placed on the lower base 201, all upper limiting plates 303 and all lower limiting plates 203 are embedded one by one, the inner surface of each upper limiting plate 303 is attached to 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 limiting plates 303 on the upper base 301 and the lower limiting plates 203 on the lower base 201 are inserted staggered, each groove 304 is aligned with the upper end of each PDC composite sheet 5, the upper base 301 is lightly tapped with a rubber hammer, all upper limiting plates 303 and all lower limiting plates 203 are embedded, and the upper end of each PDC composite sheet 5 is embedded in each groove 304, so that each PDC composite sheet 5 is fixed.

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

[0059] Then the assembled vacuum brazing PDC thrust bearing manufacturing device is sent into a vacuum brazing furnace as a whole, and ZKR-2FH vacuum brazing furnace is used in this example. First, low vacuum operation is used to evacuate the furnace, and high vacuum operation is started when the vacuum degree reaches the high limit of the low vacuum circuit. When the vacuum degree in the furnace reaches 1×10- 2Pa starts to heat, the initial heating rate is not too fast, the recommended 5-10 ℃ / min; in order to ensure that the solder 4 melting temperature inside and outside the assembly is basically the same, the capillary action can be well played, when heating to the solder 4 solidus temperature below 50-100 ℃ range (i.e. 530 ℃-580 ℃) heating rate is not too fast, the recommended heating rate is not more than 5 ℃ / min; in order to avoid the segregation of solder 4 and make the liquidus temperature increase, in the melting temperature range of solder 4 (i.e. 630-680 ℃) need faster heating, the recommended heating rate is 15 ℃ / min or more, heating to 700 ℃ need to be kept for 0.5-1h.

[0060] S5, the solder 4 cooling PDC composite sheet 5 and the bearing base 1 is welded.

[0061] Then close the vacuum brazing furnace heating button, the workpiece furnace to room temperature (25 ℃).

[0062] It should be noted that, in the process of heating, holding, cooling to room temperature, the furnace needs to be kept in high vacuum environment, after cooling to room temperature, start exhaust, take out the bearing base 1 workpiece, disassembly.

[0063] In this paper, the front, back, up, down and other orientation words are defined by the position of the parts in the drawing and the position of the parts relative to each other in the drawing, only to express the technical scheme clearly and conveniently. It should be understood that they are relative concepts, which can be changed accordingly according to different ways of use and placement, and the use of the orientation words should not limit the scope of the application.

[0064] In the case of no conflict, the above-mentioned embodiments and features in the embodiments can be combined with each other. The above-mentioned only for the preferred embodiments of the present application, and not to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the protection scope of the present application.

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, wherein the upper limit plates are spaced apart on a first circumference on the lower surface of the upper base, and the lower surface of the upper base is provided with a plurality of grooves within the first circumference; A lower mold, comprising a lower base and a plurality of arc-shaped lower limit plates, wherein the lower limit plates are spaced apart and arranged 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 fasteners, the upper mold is placed on the lower mold, the fasteners detachably connect the upper mold and the lower mold, 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 according to 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. The vacuum brazing PDC thrust bearing manufacturing device according to 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 at equal intervals on the upper base, and the lower limit plates are arranged at equal intervals on the lower base.

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

5. The vacuum brazing PDC thrust bearing manufacturing device according to 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. The vacuum brazing PDC thrust bearing manufacturing device according to claim 1, characterized in that: The upper mold also includes an upper limit frustum, which is arranged on the lower surface of the upper base, and each of the grooves surrounds the upper limit frustum. The lower mold also includes a lower limit frustum, which is arranged on the lower surface of the lower base. The upper limit frustum and the lower limit frustum 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 according to claim 6, characterized in that: The sum of the heights of the upper limit frustum and the lower limit frustum is no 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. Place the bearing base on the lower base so that the outer wall of the bearing base fits in contact with the inner surface of each lower limit plate, and place a PDC composite sheet on the solder in each blind hole, with the PDC composite sheet having a clearance fit with the blind hole and the upper end extending 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 fitted 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 with fasteners, and placing the entire base 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. The method for manufacturing a vacuum brazed PDC thrust bearing according to claim 8, wherein: In step S4, the vacuum brazing is heated to 700° C. and kept warm for 30 to 60 minutes, with a heating rate of 5 to 10° C. / min.

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