Thermal shock resistant silicon nitride ceramic bearing ball forming die and preparation process

Abstract

The application relates to the field of bearing ball preparation, and discloses a forming die and a preparation process of a thermal shock-resistant silicon nitride ceramic bearing ball, which comprises a die base, a DC motor is installed at the top of the die base, a transmission rod is rotationally connected to the top of the die base, a guide rod is fixedly connected to the top of the die base, the output end of the DC motor is fixedly connected with one end of the transmission rod, a guide screw is fixedly connected to one end of the transmission rod, and a sliding frame is threadedly connected to the outside of the guide screw. The die plate is arranged to slide on the top of the mounting base through the sliding T block, and is limited through the limiting block; when the user pushes the push block, the limiting block can be retracted into the limiting body, the die plate can be conveniently disassembled, disassembled and installed, the die plate can be conveniently disassembled, replaced and cleaned, and the problem of inconvenient disassembly and installation of the die plate is solved.

Description

Technical Field

[0001] This invention relates to the field of bearing ball preparation technology, specifically to a molding die and preparation process for a thermal shock resistant silicon nitride ceramic bearing ball. Background Technology

[0002] Thermal shock resistant silicon nitride ceramic bearing balls are high-performance bearing rolling elements made of silicon nitride ceramic material. They have excellent thermal shock resistance, meaning they can maintain structural integrity and stable mechanical properties even under drastic temperature changes. They can be used in extreme thermal shock environments such as rocket engine exhaust nozzles and aero-engine main shafts. They are one of the few single-piece ceramic materials that can withstand engine thermal gradients.

[0003] Traditional molds for forming thermal shock resistant silicon nitride ceramic bearing balls are mainly produced through isostatic pressing or injection molding processes. The principle is to use high pressure to uniformly press ceramic powder to form a dense and regularly shaped ball blank, laying the foundation for subsequent sintering and precision machining.

[0004] The inventors of this application discovered in their research that the core defect of the above-mentioned prior art is that: when using the molding mold of the traditional thermal shock resistant silicon nitride ceramic bearing ball, the mold is usually fixed by bolts. However, in the environment in which the molding mold is used, the molding mold will only be subjected to downward pressing force. Therefore, the bolt fixing method will only make it inconvenient to disassemble the molding mold of the thermal shock resistant silicon nitride ceramic bearing ball for replacement or cleaning. Summary of the Invention

[0005] This invention provides a molding die and manufacturing process for thermal shock resistant silicon nitride ceramic bearing balls, solving the problem of inconvenient disassembly of the molding die and achieving convenient replacement or cleaning of the molding die.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a molding die for a thermal shock resistant silicon nitride ceramic bearing ball, comprising a die base, a DC motor mounted on the top of the die base, a transmission rod rotatably connected to the top of the die base, a guide rod fixedly connected to the top of the die base, an output end of the DC motor fixedly connected to one end of the transmission rod, a guide screw fixedly connected to one end of the transmission rod, a sliding frame threaded onto the external of the guide screw, a servo motor mounted on one side of the sliding frame, an output end of the servo motor fixedly connected to a mounting base, a sliding T-block slidably connected inside the mounting base, a die plate fixedly connected to the top of the sliding T-block, a limiting body fixedly connected to one side of the mounting base, a telescopic rod fixedly connected inside the limiting body, a limiting block fixedly connected to one end of the telescopic rod, a spring fixedly connected to one side of the limiting block, and a lever fixedly connected to the outside of the limiting block.

[0007] By adopting the above technical solution, the mold plate slides on the top of the mounting base using a sliding T-block and is limited by a limiting block. When the user pushes the lever, the limiting block can retract into the interior of the limiting body, facilitating the disassembly of the mold plate. This allows the mold plate to be easily disassembled and installed, making it convenient for subsequent disassembly, replacement, and internal cleaning, thus solving the problem of inconvenient disassembly and installation of the mold plate.

[0008] Preferably, the top of the mold plate has a mold groove, one side of the mounting base is slidably connected to the outside of the guide rod, a transmission pulley is fixedly connected to the outside of the transmission rod, a transmission belt is driven to the outside of the transmission pulley, a first linkage pulley is fixedly connected to the outside of the transmission rod, a motor frame is fixedly connected to the top of the mold base, a fixing frame is fixedly connected to the bottom of the motor frame, a second linkage pulley is rotatably connected to one side of the fixing frame, and a linkage belt is driven to the outside of the second linkage pulley through the outside of the first linkage pulley.

[0009] Preferably, one side of the second linkage pulley is fixedly connected to a pulley gear column through the inside of the fixing frame, and the inside of the motor frame is slidably connected to an inner sliding plate.

[0010] Preferably, a plug rod is fixedly connected to one side of the inner slide plate, and a movable toothed plate is fixedly connected to the bottom of the inner slide plate, with the bottom of the movable toothed plate meshing with the top of the pulley gear column.

[0011] Preferably, an electric actuator is installed on the top of the motor frame, and a stamping plate is fixedly connected to the output end of the electric actuator. Insertion slots are provided on both sides of the stamping plate.

[0012] By adopting the above technical solution, the mounting base slides on top of the mold base. During the movement of the mounting base, the pulley rotates due to belt drive, causing the inner slide plate and the movable toothed plate to move as a whole. The insertion rod then disengages from the stamping plate, allowing the stamping plate to descend freely. Similarly, when the stamping plate rises after stamping, the movement of the mounting base causes the insertion rod to re-insert into the insertion slot for limiting. This further ensures that the stamping plate can only descend freely after the mold plate moves to the bottom of the stamping plate, effectively assisting in limiting the descent of the stamping plate and solving the problem that the stamping plate cannot lock itself after stamping.

[0013] Preferably, a bottom toothed plate is fixedly connected to the bottom of the mounting base, an abutment base is fixedly connected to the top of the mold base, and a limit rod is fixedly connected inside the abutment base.

[0014] Preferably, the limiting rod is slidably connected to an abutment rod, the abutment rod is slidably connected to the inside of the abutment base, a sliding toothed rod is fixedly connected to one side of the abutment rod, and an auxiliary rod is rotatably connected to the top of the abutment rod.

[0015] Preferably, a rotating rod is rotatably connected inside the abutment base, a transmission gear is fixedly connected to the outside of the rotating rod, and transmission gears are fixedly connected to both ends of the rotating rod, with one side of the transmission gear meshing with the outside of the sliding gear.

[0016] Preferably, an injection molding frame is fixedly connected to the top of the mold base, an injection molding plate is fixedly connected to the top of the injection molding frame, and an injection molding tube is installed inside the injection molding plate.

[0017] Preferably, a process for preparing a thermal shock resistant silicon nitride ceramic bearing ball includes the following steps: S1. First, the raw materials are ground and mixed to prepare silicon nitride powder, sintering aid and dispersant are added to the grinding media in proportion and ball milled to obtain ceramic slurry or mixed powder with uniform particle size and stable dispersion. S2. Subsequently, the pulverized and ground raw materials are injection molded into spherical shapes. The powder mixture is conveyed to the mold plate through injection molding, and after the stamping plate is lowered, it is stamped into shape, and the raw material dry powder is stamped into a ceramic bearing ball blank with a predetermined size and shape. S3. Further screening of spherical grinding balls: After sintering the ceramic bearing ball green blank obtained by stamping to form hard spheres, the balls are screened by aperture grading or sorting device to remove spheres with shape deviation and size deviation, and to obtain screened spheres with size consistency that meet the requirements. S4. Finally, the screened grinding balls are polished and ground. The screened balls are subjected to coarse grinding, fine grinding and polishing in sequence to remove surface defects and reduce surface roughness, and finally obtain silicon nitride ceramic bearing balls with high surface quality and thermal shock resistance.

[0018] By adopting the above technical solution, the transmission gear column and the bottom gear plate cause the transmission gear column to rotate when the mounting base moves, which in turn drives the transmission gear to rotate. At the same time, after the sliding gear rod and the abutment rod rise, the abutment rod and the auxiliary rod abut against the bottom of the mounting base. This ensures that the mold plate is only abutted and supported after it moves to the bottom of the stamping plate, effectively ensuring the smooth movement of the mold plate while reducing the gap between the bottom of the mold plate and the abutment base when the stamping plate is pressed, thus improving the stability of the mold plate during stamping.

[0019] This invention provides a molding die for thermal shock resistant silicon nitride ceramic bearing balls. It has the following beneficial effects: 1. This invention sets up a mold plate that slides on the top of the mounting base using a sliding T-block and is limited by a limiting block. When the user pushes the lever, the limiting block retracts into the interior of the limiting body, facilitating the disassembly of the mold plate. This allows for convenient disassembly and installation of the mold plate, making it easier to replace and clean the interior of the mold plate, thus solving the problem of inconvenient disassembly and installation of the mold plate.

[0020] 2. This invention sets up a mounting base that slides on top of the mold base. During the movement of the mounting base, the pulley is driven by a belt, causing the pulley gear column to rotate. This causes the inner slide plate and the movable toothed plate to move as a whole, and the insertion rod disengages from the stamping plate. At this time, the stamping plate can descend freely. Similarly, when the stamping plate rises after stamping, the movement of the mounting base will cause the insertion rod to re-insert into the insertion slot for limiting. This further ensures that the mold plate can only descend freely after it moves to the bottom of the stamping plate, effectively assisting in limiting the descent of the stamping plate and solving the problem that the stamping plate cannot lock itself after stamping.

[0021] 3. By setting a transmission gear column and a bottom gear plate, the movement of the mounting base causes the transmission gear column to rotate, which in turn drives the transmission gear to rotate. At the same time, after the sliding gear rod and the abutment rod rise, the abutment rod and the auxiliary rod abut against the bottom of the mounting base. This ensures that the mold plate is only abutted and supported after it moves to the bottom of the stamping plate. This effectively ensures the smooth movement of the mold plate while reducing the gap between the bottom of the mold plate and the abutment base when the mold plate is pressed by the stamping plate, thus improving the stability of the mold plate during stamping. Attached Figure Description

[0022] Figure 1 This is an overall perspective view of the present invention; Figure 2 This is a side view of the present invention; Figure 3 This is a schematic diagram of the mold plate of the present invention; Figure 4 This is a schematic diagram of the abutment base of the present invention; Figure 5 This is a schematic diagram of the motor frame of the present invention; Figure 6 This is a cross-sectional view of the abutment base of the present invention; Figure 7 This is an enlarged view of point A in the present invention; Figure 8 This is an enlarged view of section B of the present invention; Figure 9 This is an enlarged view of point C in the present invention; Figure 10 This is an enlarged view of point D in the present invention.

[0023] The components include: 1. Mold base; 2. Guide rod; 3. Guide screw; 4. Injection frame; 5. Injection plate; 6. Injection tube; 7. Motor frame; 8. Electric actuator; 9. Stamping plate; 10. Mold groove; 11. Sliding frame; 12. Mounting base; 13. Mold plate; 14. Abutment base; 15. Sliding T-block; 16. Bottom toothed plate; 17. Servo motor; 18. Rotating rod; 19. Transmission gear column; 20. Transmission gear; 21. Abutment rod; 22. Sliding... 23. Gear rack; 24. Auxiliary rod; 25. Limiting rod; 26. DC motor; 27. Transmission rod; 28. First linkage pulley; 29. ​​Linkage belt; 30. Fixing frame; 31. Second linkage pulley; 32. Transmission pulley; 33. Transmission belt; 34. Limiting body; 35. Telescopic rod; 36. Limiting block; 37. Pulley block; 38. Spring; 39. Inner sliding plate; 40. Insertion rod; 41. Insertion slot; 42. Pulley gear column; 43. Movable gear plate. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see the appendix Figure 1 - Appendix Figure 10 This invention provides a molding die for a thermal shock resistant silicon nitride ceramic bearing ball, including a die base 1. A DC motor 25 is mounted on the top of the die base 1. A transmission rod 26 is rotatably connected to the top of the die base 1. A guide rod 2 is fixedly connected to the top of the die base 1. The output end of the DC motor 25 is fixedly connected to one end of the transmission rod 26. A guide screw 3 is fixedly connected to one end of the transmission rod 26. A sliding frame 11 is threadedly connected to the outside of the guide screw 3. A servo motor 17 is mounted on one side of the sliding frame 11. A mounting base 12 is fixedly connected to the output end of the servo motor 17. A sliding T-block 15 is slidably connected inside the mounting base 12. A die plate 13 is fixedly connected to the top of the sliding T-block 15. A limiting body 33 is fixedly connected to one side of the mounting base 12. A telescopic rod 34 is fixedly connected inside the limiting body 33. A limiting block 35 is fixedly connected to one end of the telescopic rod 34. A spring 37 is fixedly connected to one side of the limiting block 35. A toggle block 36 is fixedly connected to the outside of the limiting block 35.

[0026] Specifically, after the DC motor 25 is started, the transmission rod 26 and the guide screw 3 rotate, which drives the mounting base 12 to slide outside the guide rod 2. The servo motor 17 can drive the mounting base 12 to rotate as a whole, thereby assisting in material discharge. This further enables the mold plate 13 to move laterally and rotate, allowing the mold plate 13 to move to a different position as needed.

[0027] The mold plate 13 can slide inside the mounting base 12 using the sliding T-block 15, and the limiting block 35 can be pushed by the pusher block 36 and retracted into the limiting body 33, causing the telescopic rod 34 and spring 37 to be compressed, which facilitates the disassembly of the mold plate 13 and the sliding T-block 15. Furthermore, the mold plate 13 and the sliding T-block 15 can use the inclined side of the limiting block 35 to retract into the limiting body 33, which facilitates the installation of the mold plate 13 and the sliding T-block 15.

[0028] Please see the appendix Figure 4 , Figure 5 , Figure 7 , Figure 9 and attached Figure 10 The top of the mold plate 13 is provided with a mold groove 10. One side of the mounting base 12 is slidably connected to the outside of the guide rod 2. The outside of the transmission rod 26 is fixedly connected to the transmission pulley 31. The outside of the transmission pulley 31 is connected to the transmission belt 32. The outside of the transmission rod 26 is fixedly connected to the first linkage pulley 27. The top of the mold base 1 is fixedly connected to the motor frame 7. The bottom of the motor frame 7 is fixedly connected to the fixing frame 29. One side of the fixing frame 29 is rotatably connected to the second linkage pulley 30. The outside of the second linkage pulley 30 is connected to the linkage belt 28 through the outside of the first linkage pulley 27.

[0029] The second linkage pulley 30 is fixedly connected to a pulley gear column 41 through the inside of the fixing frame 29 on one side, and the motor frame 7 is slidably connected to an inner slide plate 38.

[0030] A plug rod 39 is fixedly connected to one side of the inner slide plate 38, and a movable toothed plate 42 is fixedly connected to the bottom of the inner slide plate 38. The bottom of the movable toothed plate 42 meshes with the top of the pulley gear column 41.

[0031] An electric actuator 8 is mounted on the top of the motor frame 7. The output end of the electric actuator 8 is fixedly connected to a stamping plate 9. Insertion slots 40 are provided on both sides of the stamping plate 9.

[0032] Specifically, during the movement of the mold plate 13, the transmission rod 26 and the first linkage pulley 27 will also rotate synchronously, and the linkage belt 28 will drive the second linkage pulley 30 to rotate, while driving the pulley gear column 41 to rotate. After the meshing movable tooth plate 42 moves, it will drive the inner slide plate 38 to retract into the motor frame 7, and the plug rod 39 will disengage from the plug slot 40, so that the stamping plate 9 is no longer limited. Similarly, when the mold plate 13 moves away from the stamping plate 9, the stamping plate 9 will be limited again.

[0033] When the mold plate 13 moves to the bottom of the stamping plate 9, the electric push rod 8 drives the stamping plate 9 to descend, so that the bottom structure of the stamping plate 9 is inserted into the mold groove 10, thereby achieving the function of pressure forming.

[0034] Please see the appendix Figure 1 , Figure 3 , Figure 5 and attached Figure 6 The bottom of the mounting base 12 is fixedly connected to a bottom toothed plate 16, and the top of the mold base 1 is fixedly connected to an abutment base 14. The abutment base 14 is fixedly connected to a limit rod 24 inside.

[0035] The limiting rod 24 is externally slidably connected to an abutment rod 21, which is externally slidably connected to the inside of the abutment base 14. A sliding toothed rod 22 is fixedly connected to one side of the abutment rod 21, and an auxiliary rod 23 is rotatably connected to the top of the abutment rod 21.

[0036] A rotating rod 18 is rotatably connected inside the base 14, and a transmission gear 19 is fixedly connected to the outside of the rotating rod 18. Transmission gears 20 are fixedly connected to both ends of the rotating rod 18, and one side of the transmission gear 20 meshes with the outside of the sliding gear 22.

[0037] An injection frame 4 is fixedly connected to the top of the mold base 1, and an injection plate 5 is fixedly connected to the top of the injection frame 4. An injection tube 6 is installed inside the injection plate 5.

[0038] Specifically, the movement of the mounting base 12 will cause the bottom toothed plate 16 to move until the bottom toothed plate 16 contacts and meshes with the transmission toothed column 19, and the transmission toothed column 19 rotates, which in turn drives the transmission gear 20 to rotate. After the sliding toothed rod 22 rises, the abutment rod 21 slides outside the limiting rod 24 until the auxiliary rod 23 at the top of the abutment rod 21 contacts the bottom of the mounting base 12, which then supports the mounting base 12. At this time, the mounting base 12 is also completely at the bottom of the stamping plate 9.

[0039] After the mold plate 13 moves to the bottom of the injection tube 6, the injection tube 6 injects an equal amount of mixed powder of silicon nitride powder, sintering aid and dispersant into the mold groove 10, and then the mold plate 13 moves to the bottom of the stamping plate 9 to be stamped.

[0040] A process for preparing thermal shock resistant silicon nitride ceramic bearing balls includes the following steps: S1. First, the raw materials are ground and mixed to prepare silicon nitride powder, sintering aid and dispersant are added to the grinding media in proportion and ball milled to obtain ceramic slurry or mixed powder with uniform particle size and stable dispersion. S2. Subsequently, the pulverized and ground raw material is injection molded into a spherical shape. The powder mixture is conveyed to the mold plate 13 through injection molding. After the stamping plate 9 is lowered, it is stamped into shape, and the dry powder of the raw material is stamped into a ceramic bearing ball blank with a predetermined size and shape. S3. Further screening of spherical grinding balls: After sintering the ceramic bearing ball green blank obtained by stamping to form hard spheres, the balls are screened by aperture grading or sorting device to remove spheres with shape deviation and size deviation, and to obtain screened spheres with size consistency that meet the requirements. S4. Finally, the screened grinding balls are polished and ground. The screened balls are subjected to coarse grinding, fine grinding and polishing in sequence to remove surface defects and reduce surface roughness, and finally obtain silicon nitride ceramic bearing balls with high surface quality and thermal shock resistance.

[0041] Specifically, after the DC motor 25 starts, it causes the transmission rod 26 and the guide screw 3 to rotate, which in turn drives the mounting base 12 to slide outside the guide rod 2. The servo motor 17 can also drive the mounting base 12 to rotate as a whole, thus assisting in material discharge. Furthermore, it enables the mold plate 13 to move laterally and rotate, allowing it to move as needed. The mold plate 13 can slide inside the mounting base 12 using the sliding T-block 15, and the limiting block 35 can retract into the limiting body 33 after being pushed by the lever 36. The expansion joint compresses the telescopic rod 34 and spring 37, facilitating the disassembly of the mold plate 13 and sliding T-block 15. The mold plate 13 and sliding T-block 15 can also utilize the inclined side of the limiting block 35 to retract the limiting block 35 into the limiting body 33, facilitating the installation of the mold plate 13 and sliding T-block 15. During the movement of the mold plate 13, the transmission rod 26 and the first linkage pulley 27 rotate synchronously, and the linkage belt 28 drives the second linkage pulley 30 to rotate, simultaneously driving the pulley gear column 41 to rotate, causing the meshing movable toothed plate 42 to move. The inner slide plate 38 retracts into the motor frame 7, and the insertion rod 39 disengages from the insertion slot 40, so that the stamping plate 9 is no longer limited. Similarly, when the mold plate 13 moves away from the stamping plate 9, the stamping plate 9 will be limited again. When the mold plate 13 moves to the bottom of the stamping plate 9, the electric push rod 8 drives the stamping plate 9 to descend, so that the bottom structure of the stamping plate 9 is inserted into the mold slot 10, thereby achieving the function of pressure forming. The movement of the mounting base 12 will drive the bottom toothed plate 16 to move until the bottom toothed plate 16 contacts and meshes with the transmission toothed column 19, and the transmission toothed column... After rotation of 19, the transmission gear 20 is driven to rotate, causing the sliding toothed rod 22 to rise. The abutment rod 21 slides outside the limiting rod 24 until the auxiliary rod 23 at the top of the abutment rod 21 contacts the bottom of the mounting base 12, thus supporting the mounting base 12. At this time, the mounting base 12 is also completely at the bottom of the stamping plate 9. After the mold plate 13 moves to the bottom of the injection tube 6, the injection tube 6 injects an equal amount of mixed powder of silicon nitride powder, sintering aid and dispersant into the mold groove 10. Then, the mold plate 13 moves to the bottom of the stamping plate 9 and is stamped.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A molding die for a thermal shock resistant silicon nitride ceramic bearing ball, comprising a die base (1), characterized in that, A DC motor (25) is mounted on the top of the mold base (1). A transmission rod (26) is rotatably connected to the top of the mold base (1). A guide rod (2) is fixedly connected to the top of the mold base (1). The output end of the DC motor (25) is fixedly connected to one end of the transmission rod (26). A guide screw (3) is fixedly connected to one end of the transmission rod (26). A sliding frame (11) is threaded onto the external side of the guide screw (3). A servo motor (17) is mounted on one side of the sliding frame (11). The output end of the servo motor (17) is fixedly connected to the guide screw (3). A mounting base (12) is fixedly connected to the mounting base (12). A sliding T-block (15) is slidably connected inside the mounting base (12). A mold plate (13) is fixedly connected to the top of the sliding T-block (15). A limiting body (33) is fixedly connected to one side of the mounting base (12). A telescopic rod (34) is fixedly connected inside the limiting body (33). A limiting block (35) is fixedly connected to one end of the telescopic rod (34). A spring (37) is fixedly connected to one side of the limiting block (35). A toggle block (36) is fixedly connected to the outside of the limiting block (35).

2. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 1, characterized in that, The mold plate (13) has a mold groove (10) on its top. One side of the mounting base (12) is slidably connected to the outside of the guide rod (2). A transmission pulley (31) is fixedly connected to the outside of the transmission rod (26). A transmission belt (32) is driven to the outside of the transmission pulley (31). A first linkage pulley (27) is fixedly connected to the outside of the transmission rod (26). A motor frame (7) is fixedly connected to the top of the mold base (1). A fixing frame (29) is fixedly connected to the bottom of the motor frame (7). A second linkage pulley (30) is rotatably connected to one side of the fixing frame (29). A linkage belt (28) is driven to the outside of the second linkage pulley (30) through the outside of the first linkage pulley (27).

3. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 2, characterized in that, The second linkage pulley (30) is fixedly connected to a pulley gear column (41) through the inside of the fixing frame (29) on one side, and the motor frame (7) is slidably connected to an inner slide plate (38).

4. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 3, characterized in that, A plug rod (39) is fixedly connected to one side of the inner slide plate (38), and a movable toothed plate (42) is fixedly connected to the bottom of the inner slide plate (38). The bottom of the movable toothed plate (42) meshes with the top of the pulley gear column (41).

5. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 2, characterized in that, An electric push rod (8) is installed on the top of the motor frame (7). The output end of the electric push rod (8) is fixedly connected to a stamping plate (9). Insertion slots (40) are provided on both sides of the stamping plate (9).

6. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 1, characterized in that, The bottom of the mounting base (12) is fixedly connected to a bottom toothed plate (16), and the top of the mold base (1) is fixedly connected to an abutment base (14). The interior of the abutment base (14) is fixedly connected to a limit rod (24).

7. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 6, characterized in that, The limiting rod (24) is slidably connected to the outside of the abutting rod (21), the abutting rod (21) is slidably connected to the inside of the abutting base (14), a sliding toothed rod (22) is fixedly connected to one side of the abutting rod (21), and an auxiliary rod (23) is rotatably connected to the top of the abutting rod (21).

8. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 7, characterized in that, The abutment base (14) is rotatably connected to a rotating rod (18), and a transmission gear (19) is fixedly connected to the outside of the rotating rod (18). Both ends of the rotating rod (18) are fixedly connected to transmission gears (20), and one side of the transmission gear (20) meshes with the outside of the sliding gear (22).

9. The molding die for a thermal shock resistant silicon nitride ceramic bearing ball according to claim 1, characterized in that, The top of the mold base (1) is fixedly connected to an injection frame (4), the top of the injection frame (4) is fixedly connected to an injection plate (5), and an injection tube (6) is installed inside the injection plate (5).

10. A process for preparing thermal shock resistant silicon nitride ceramic bearing balls, characterized in that, The molding die used for the thermal shock resistant silicon nitride ceramic bearing ball according to any one of claims 1-9, the manufacturing process includes the following steps: S1. First, the raw materials are ground and mixed to prepare silicon nitride powder, sintering aid and dispersant are added to the grinding media in proportion and ball milled to obtain ceramic slurry or mixed powder with uniform particle size and stable dispersion. S2. Subsequently, the raw materials after crushing and grinding are injection molded into spherical shapes. The powder mixture is conveyed to the mold plate (13) through injection molding. After the stamping plate (9) is lowered, it is stamped into shape, and the dry powder of the raw materials is stamped into ceramic bearing ball blanks with predetermined size and shape. S3. Further screening of spherical grinding balls: After sintering the ceramic bearing ball green blank obtained by stamping to form hard spheres, the balls are screened by aperture grading or sorting device to remove spheres with shape deviation and size deviation, and to obtain screened spheres with size consistency that meet the requirements. S4. Finally, the screened grinding balls are polished and ground. The screened balls are subjected to coarse grinding, fine grinding and polishing in sequence to remove surface defects and reduce surface roughness, and finally obtain silicon nitride ceramic bearing balls with high surface quality and thermal shock resistance.

Images