A gear mold, a gear ring mold, and a gear and gear ring assembly.

Abstract

This invention discloses a gear mold, a gear ring mold, and a gear and gear ring assembly. The gear mold includes a first upper punch mechanism, a first lower punch mechanism, and a first intermediate mold. The first upper punch mechanism includes a first upper punch seat and a first outer upper punch; the first lower punch mechanism includes a first lower mandrel and a first outer lower punch; the first intermediate mold includes a first mold base and a first mold core. The center of the first mold core is provided with a first through hole for the first outer upper punch and the first lower punch mechanism to pass through. The first outer upper punch, the first mold core, the first lower mandrel, and the first outer lower punch can cooperate to form a first forming cavity. The inner wall of the first mold core is provided with a plurality of first tooth grooves evenly distributed circumferentially. The first tooth grooves are located in the first forming cavity, and the bottom of the first tooth grooves is provided with a first chamfer. The gear mold of the first aspect embodiment of this invention can press out a gear in one operation, and the chamfer on the gear teeth for guidance can be directly formed, reducing processing time and cost.

Description

Technical Field

[0001] This invention relates to the field of mold technology, and in particular to a gear mold, a gear ring mold, and a gear and gear ring assembly. Background Technology

[0002] Traditional gearboxes consist of gears and a ring gear assembly. Transmission occurs through the meshing of the gears and ring gear, with the gears able to engage or disengage axially to switch between transmission and non-transmission states, thus completing gear shifting. In current gearboxes, when the gears and ring gear slide axially towards each other, the uncertainty of the tooth positions at their contact points can easily lead to tooth overlap and collision. This can result in minor issues like the gear not smoothly engaging the ring gear, causing shifting to become stuck or impossible. In severe cases, the impact can cause tooth breakage, severely damaging the contact surfaces and reducing the lifespan of both the gears and ring gear.

[0003] A gear positioning structure has been proposed in related technologies. After the gear is formed, a chamfered bevel is machined on the gear teeth. The chamfered bevel acts as a guide. For meshing gear transmission structures with axial movement, during the process of the two gears moving towards each other and contacting each other in the axial direction and then sliding into meshing, the chamfered bevel can effectively guide the teeth of the two gears into the meshing position to achieve precise positioning. However, the machining method increases the processing time and cost and reduces production efficiency. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a gear mold that can press gears in one operation, and the chamfers on the gear teeth used for guidance can be directly formed, reducing processing time and cost and improving production efficiency.

[0005] Secondly, the present invention also proposes a gear ring mold.

[0006] Thirdly, the present invention also proposes a gear and gear ring assembly made using the above-mentioned gear mold and gear ring mold.

[0007] In a first aspect, according to the present invention, a gear mold includes a first upper punch mechanism, a first lower punch mechanism, and a first intermediate mold. The first upper punch mechanism includes a first upper punch seat and a first outer upper punch, the first upper punch seat being fixedly connected to the first outer upper punch, and a third through hole extending vertically is provided in the middle of the first outer upper punch. The first lower punch mechanism includes a first lower mandrel and a first outer lower punch, the lower end of the first lower mandrel being fixedly connected to a first mandrel base, the first mandrel base being connected to a first cylinder for pushing and resetting the first lower mandrel, and the first outer lower punch being fitted onto the outer side of the first lower mandrel. The first outer lower punch can move relative to the first mold base and the first mold core. The first mold base is located between the first upper punch mechanism and the first lower punch mechanism. The first mold core is provided inside the first mold base. The first mold core has a first through hole in the middle for the first outer upper punch and the first lower punch mechanism to pass through. The first outer upper punch, the first mold core, the first lower mandrel and the first outer lower punch can cooperate to form a first forming cavity. The inner wall of the first mold core is provided with a plurality of first tooth grooves evenly distributed in the circumference. The first tooth grooves are located in the first forming cavity. The ends of the first tooth grooves are provided with a first chamfer.

[0008] The gear mold according to the above embodiments of the present invention has at least the following beneficial effects:

[0009] Gears can be pressed out in one go, and the chamfers on the gear teeth used for guidance can be directly formed, eliminating machining processes, reducing processing time and costs, and improving processing efficiency.

[0010] According to some embodiments of the present invention, each of the first tooth grooves has two first chamfers at its end, and the two first chamfers are symmetrically distributed along the central axis of the first tooth groove.

[0011] According to some embodiments of the present invention, the first lower punch mechanism further includes a first inner lower punch, the first inner lower punch is fitted on the outer side of the first lower mandrel, the first outer lower punch is fitted on the outer side of the first inner lower punch, the first outer lower punch, the first inner lower punch and the first lower mandrel can move relative to each other, the first inner lower punch, the first outer lower punch and the first lower mandrel can cooperate to form a boss forming cavity, the boss forming cavity is connected to the first forming cavity and is located directly below the first forming cavity, and a plurality of second tooth grooves are evenly distributed on the inner wall of the first outer lower punch, the second tooth grooves are located in the boss forming cavity.

[0012] Secondly, according to the present invention, a gear ring mold includes a second upper punch mechanism, a second lower punch mechanism, and a second middle mold. The second upper punch mechanism includes a second upper punch seat, a second outer upper punch, and a first inner upper punch. The second upper punch seat is fixedly connected to the second outer upper punch. The first inner upper punch passes through the middle of the second outer upper punch. A forming part is provided at the lower part of the first inner upper punch. A plurality of third tooth grooves are evenly distributed circumferentially on the outer wall of the forming part. The ends of the third tooth grooves are provided with second chamfers. The second lower punch mechanism includes a second lower mandrel and a second outer lower punch. A second mandrel base is fixedly connected to the lower end of the second lower mandrel. The second mandrel base is connected to a pushing and resetting mechanism. The second cylinder of the second lower mandrel, the second outer lower punch is fitted on the outer side of the second lower mandrel, the second lower mandrel and the second outer lower punch can move relative to each other; the second middle mold includes a second mold base and a second mold core, the second mold base is located between the second upper punch mechanism and the second lower punch mechanism, the second mold core is provided inside the second mold base, the second mold core is provided in the middle of the second mold core for the second outer upper punch, the first inner upper punch and the second lower punch mechanism to pass through, the second outer upper punch, the first inner upper punch, the second mold core, the second lower mandrel and the second outer lower punch can cooperate to form a second molding cavity, the molding part can be inserted into the second molding cavity.

[0013] The gear ring mold according to the above embodiments of the present invention has at least the following beneficial effects:

[0014] Gear rings can be pressed out in one go, and the chamfers on the teeth of the gear ring used for guidance can be directly formed, eliminating machining processes, reducing processing time and costs, and improving processing efficiency.

[0015] According to some embodiments of the present invention, each of the third tooth grooves is provided with two second chamfers at its end, and the two second chamfers are symmetrically distributed along the central axis of the third tooth groove.

[0016] Thirdly, according to the present invention, a gear and gear ring assembly includes a gear and a gear ring, wherein the gear is capable of meshing with the gear ring and sliding relative to it axially, the outer peripheral wall of the gear is provided with a plurality of uniformly distributed first teeth, and the inner peripheral wall of the gear ring is correspondingly provided with a plurality of uniformly distributed second teeth, one end of the first teeth is provided with a third chamfer, and one end of the second teeth is provided with a fourth chamfer, the third chamfer and the fourth chamfer being arranged at opposite ends of the gear and the gear ring sliding towards each other.

[0017] The gear and gear ring assembly according to the above embodiments of the present invention has at least the following beneficial effects:

[0018] During the process of the gear and the gear ring moving towards each other in the axial direction and then sliding into meshing, the chamfered surfaces of the two parts can guide the teeth of the gear to smoothly slide into the corresponding meshing position of the gear ring, avoiding tooth collision due to the overlap of the teeth of the two parts, preventing the teeth of the gear and the gear ring from breaking, and increasing the service life of the gear and the gear ring.

[0019] According to some embodiments of the present invention, each of the first teeth has two third chamfers at its end, the two third chamfers being symmetrically distributed along the central axis of the first tooth, and each of the second teeth has two fourth chamfers at its end, the two fourth chamfers being symmetrically distributed along the central axis of the second tooth.

[0020] According to some embodiments of the present invention, the third chamfer extends along the outer peripheral wall edge of the gear to connect adjacent third chamfers, and the fourth chamfer extends along the inner peripheral wall edge of the gear ring to connect adjacent fourth chamfers.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0023] Figure 1 This is a schematic diagram of the powder filling state of a gear mold according to some embodiments of the present invention;

[0024] Figure 2 This is a schematic diagram of the pressing state of a gear mold according to some embodiments of the present invention;

[0025] Figure 3 These are schematic diagrams showing the demolding state of gear molds according to some embodiments of the present invention;

[0026] Figure 4 This is a partial structural schematic diagram of a gear mold according to some embodiments of the present invention;

[0027] Figure 5 This is a schematic diagram of the first molding cavity in some embodiments of the present invention;

[0028] Figure 6 yes Figure 1 Enlarged view of point A in the middle;

[0029] Figure 7 This is a top view of the first outer downward punch according to some embodiments of the present invention;

[0030] Figure 8 This is a schematic diagram of the powder filling state of the gear ring mold according to some embodiments of the present invention;

[0031] Figure 9 This is a schematic diagram of the pressing state of the gear ring mold according to some embodiments of the present invention;

[0032] Figure 10 This is a schematic diagram of the demolding state of a gear ring mold according to some embodiments of the present invention;

[0033] Figure 11 This is a partial structural schematic diagram of a gear ring mold according to some embodiments of the present invention;

[0034] Figure 12 This is a bottom view of the first inner upward thrust of some embodiments of the present invention;

[0035] Figure 13 yes Figure 8 Enlarged view at point B in the middle;

[0036] Figure 14 These are schematic diagrams of the gear structure according to some embodiments of the present invention;

[0037] Figure 15 These are schematic diagrams of the gear rings according to some embodiments of the present invention;

[0038] Figure 16 This is a schematic diagram of the structure of a gear and gear ring assembly according to some embodiments of the present invention.

[0039] In the attached figures, the following labels are used:

[0040] First upper punch mechanism 100; first upper punch seat 110; first outer upper punch 120; third through hole 130;

[0041] First lower punch mechanism 200; first lower core bar 210; first outer lower punch 220; first inner lower punch 230; first core bar base 240; boss forming cavity 250; second tooth groove 260;

[0042] First intermediate mold 300; first mold base 310; first mold core 320; first molding cavity 330; first toothed groove 340; first chamfer 341;

[0043] Second upper punch mechanism 400; second upper punch seat 410; second outer upper punch 420; first inner upper punch 430; forming part 440; third tooth groove 450; second chamfer 451;

[0044] Second lower punch mechanism 500; second lower core bar 510; second outer lower punch 520; second core bar base 530;

[0045] Second intermediate mold 600; second mold base 610; second mold core 620; second molding cavity 630;

[0046] Gear 700; First tooth 710; Third chamfer 711; Circular boss 720; Third tooth 730;

[0047] Gear ring 800; second tooth 810; fourth chamfer 811. Detailed Implementation

[0048] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0049] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0050] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0051] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0052] Reference Figures 1 to 7 According to the present invention, a gear mold includes a first upper punch mechanism 100, a first lower punch mechanism 200 and a first middle mold 300. The first upper punch mechanism 100 includes a first upper punch seat 110 and a first outer upper punch 120. The first upper punch seat 110 is fixedly connected to the first outer upper punch 120 and is connected to a gear mold support. The first outer upper punch 120 has a third through hole 130 extending in the vertical direction in the middle.

[0053] The first lower punch mechanism 200 includes a first lower core rod 210 and a first outer lower punch 220. The lower end of the first lower core rod 210 is fixedly connected to a first core rod base 240. The first core rod base 240 is connected to a first cylinder that pushes and resets the first lower core rod 210. The first outer lower punch 220 is fitted on the outside of the first lower core rod 210. The first lower core rod 210 and the first outer lower punch 220 can move relative to each other. The first outer lower punch 220 is fixedly connected to a first outer lower punch seat by screws. The first outer lower punch seat is installed on a gear mold support. The movement of the first outer lower punch seat is controlled by the gear mold support, thereby driving the first outer lower punch 220 to move.

[0054] The first intermediate mold 300 is used to form a molding cavity, including a first mold base 310 and a first mold core 320. The first mold base 310 is located between the first upper punch mechanism 100 and the first lower punch mechanism 200. The first mold base 310 is fixed on the gear mold support. The first mold core 320 is provided inside the first mold base 310. The first mold base 310 and the first mold core 320 are interference-fitted. The middle part of the first mold core 320 is provided with a first through hole for the first outer upper punch 120 and the first lower punch mechanism 200 to pass through. The first outer upper punch 120, the first mold core 320, the first lower mandrel 210 and the first outer lower punch 220 can cooperate to form a first molding cavity 330. The inner wall of the first mold core 320 is provided with a plurality of first tooth grooves 340 evenly distributed around the circumference. The first tooth grooves 340 are located in the first molding cavity 330. The end of the first tooth groove 340 is provided with a first chamfer 341.

[0055] Furthermore, in some embodiments, each first tooth groove 340 is provided with two first chamfers 341 at its end. The two first chamfers 341 are symmetrically distributed along the central axis of the first tooth groove 340. The first chamfers 341 extend along the inner wall of the first mold core 320 to connect adjacent first chamfers 341. The first chamfers 341 can also be other sizes and shapes, which can be determined according to actual needs, and will not be elaborated here.

[0056] Furthermore, in some embodiments, the first lower punch mechanism 200 further includes a first inner lower punch 230. The upper end of the first lower mandrel 210 is coaxially fitted with the first inner lower punch 230 and the first outer lower punch 220 from the inside to the outside. The first outer lower punch 220, the first inner lower punch 230 and the first lower mandrel 210 can move relative to each other. The first outer lower punch 220 and the first inner lower punch 230 are both fixedly connected to the corresponding first outer lower punch seat and the first inner lower punch seat by screws. The first outer lower punch seat and the first inner lower punch seat are both mounted on the gear mold support. The relative movement of the first outer lower punch seat and the first inner lower punch seat is controlled by the gear mold support, thereby controlling the relative movement of the first outer lower punch 220 and the first inner lower punch 230. The first inner lower punch 230, the first outer lower punch 220 and the first lower core rod 210 can cooperate to form a boss forming cavity 250. The boss forming cavity 250 is connected to the first forming cavity 330 and is located directly below the first forming cavity 330. The inner wall of the first outer lower punch 220 is evenly provided with a plurality of second tooth grooves 260. The second tooth grooves 260 are located in the boss forming cavity 250. Thus, a boss can be formed at one end of the pressed part. The outer peripheral wall of the boss has teeth to cooperate with other parts to perform meshing motion.

[0057] Specifically, before powder filling, the first cylinder continuously vents air, causing the first lower mandrel 210 to move upwards until it is level with the end face of the first mold core 320. The first outer lower punch 220 and the first inner lower punch 230 move to appropriate positions under the control of the gear mold support to form a cavity with the first mold core 320. During powder filling, the first cylinder continues to vent air, and the first lower mandrel 210 remains stationary. After powder filling is completed, the first upper punch mechanism 100 moves downwards under the control of the gear mold support, cooperating with the first mold core 320, the first lower mandrel 210, the first outer lower punch 220, and the first inner lower punch 230 to form a cavity. During pressing, the upper end face of the first lower mandrel 210 remains level with the upper end face of the first mold core 320, and the first outer upper punch 120 moves downwards so that the upper end of the first lower mandrel 210 is inserted into the third through hole 130. The first chamfer 341 at the end of the first tooth groove 340 can directly form the chamfer on the teeth of the part without the need for subsequent machining, thereby reducing machining time and cost and improving machining efficiency.

[0058] After pressing is completed, the first upper punch mechanism 100 moves upward under the control of the gear mold support, the first outer lower punch 220 remains stationary, and the first middle mold 300 moves downward under the control of the gear mold support until the part is completely removed from the first middle mold 300. Then, the first inner lower punch 230 moves upward under the control of the gear mold support, thereby ejecting the part to achieve demolding. During this process, the part first separates from the first middle mold 300 and then from the first outer lower punch 220. By adopting a step-by-step demolding method, the friction between the part and the first mold core 320 and the first outer lower punch 220 during demolding is reduced, thereby reducing the demolding force of the part.

[0059] Reference Figures 8 to 13 According to the present invention, a gear ring mold includes a second upper punch mechanism 400, a second lower punch mechanism 500, and a second middle mold 600. The second upper punch mechanism 400 includes a second upper punch seat 410, a second outer upper punch 420, and a first inner upper punch 430. The second upper punch seat 410 is fixedly connected to the second outer upper punch 420 and is connected to a gear ring mold support. The first inner upper punch 430 is provided through the middle of the second outer upper punch 420. A forming part 440 is provided at the lower part of the first inner upper punch 430. A plurality of third tooth grooves 450 are evenly distributed around the outer wall of the forming part 440. A second chamfer 451 is provided at the end of the third tooth groove 450.

[0060] The second lower punch mechanism 500 includes a second lower core rod 510 and a second outer lower punch 520. The lower end of the second lower core rod 510 is fixedly connected to a second core rod base 530. The second core rod base 530 is connected to a second cylinder that pushes and resets the second lower core rod 510. The second outer lower punch 520 is fitted on the outer side of the second lower core rod 510. The second lower core rod 510 and the second outer lower punch 520 can move relative to each other. The second outer lower punch 520 is fixedly connected to a second outer lower punch seat by screws. The second outer lower punch seat is installed on the gear ring mold support. The movement of the second outer lower punch seat is controlled by the gear ring mold support, which in turn drives the movement of the second outer lower punch 520.

[0061] The second mold 600 is used to form a molding cavity and includes a second mold base 610 and a second mold core 620. The second mold base 610 is located between the second upper punch mechanism 400 and the second lower punch mechanism 500. The second mold base 610 is fixed on the gear ring mold support. The second mold core 620 is provided inside the second mold base 610. The second mold base 610 and the second mold core 620 are interference-fitted. The middle part of the second mold core 620 is provided with a second through hole for the second outer upper punch 420, the first inner upper punch 430 and the second lower punch mechanism 500 to pass through. The second outer upper punch 420, the first inner upper punch 430, the second mold core 620, the second lower mandrel 510 and the second outer lower punch 520 can cooperate to form the second molding cavity 630. The molding part 440 can be inserted into the second molding cavity 630.

[0062] Furthermore, in some embodiments, each third tooth groove 450 is provided with two second chamfers 451 at its end. The two second chamfers 451 are symmetrically distributed along the central axis of the third tooth groove 450. The second chamfers 451 extend along the outer wall of the forming part 440 to connect adjacent second chamfers 451. The second chamfers 451 can also be other sizes and shapes, which can be determined according to actual needs, and will not be described in detail here.

[0063] Specifically, before powder filling, the second cylinder continuously vents air, causing the second lower mandrel 510 to move upwards until it is level with the end face of the second mold core 620. The second outer lower punch 520, under the control of the gear ring mold support, moves to a suitable position to form the cavity with the second mold core 620. During powder filling, the second cylinder continues to vent, and the second lower mandrel 510 remains stationary. After powder filling, the second upper punch mechanism 400 moves downwards under the control of the gear ring mold support, cooperating with the second mold core 620, the second lower mandrel 510, and the second outer lower punch 520 to form the cavity. During pressing, because the downward pressure of the second upper punch 410 on the gear ring mold support is greater than the upward pressure of the second cylinder, the forming part 440 is forced to contact the second lower mandrel 510 and move downwards together. The second chamfer 451 at the top of the third tooth groove 450 can directly form the chamfer on the teeth of the part, eliminating the need for subsequent machining, reducing processing time and cost, and improving processing efficiency.

[0064] After pressing is completed, the second upper punch mechanism 400 moves upward under the control of the gear ring mold support, and the second middle mold 600 moves downward under the control of the gear ring mold support until the part is completely ejected from the second middle mold 600. Then, the part fitted onto the second outer lower punch 520 can be removed. During this process, the part first separates from the first inner upper punch 430, and then separates from the second middle mold 600. By adopting a step-by-step demolding method, the friction between the part and the second mold core 620 and the first inner upper punch 430 during demolding is reduced, thereby reducing the demolding force of the part.

[0065] Reference Figures 14 to 16 According to the present invention, a gear and gear ring assembly includes a gear 700 and a gear ring 800. The gear 700 is capable of meshing with the gear ring 800 and sliding relative to it axially. The outer peripheral wall of the gear 700 is provided with a plurality of uniformly distributed first teeth 710, and the inner peripheral wall of the gear ring 800 is correspondingly provided with a plurality of uniformly distributed second teeth 810. One end of the first teeth 710 is provided with a third chamfer 711, and one end of the second teeth 810 is provided with a fourth chamfer 811. The third chamfer 711 and the fourth chamfer 811 are arranged at the opposite ends of the gear 700 and the gear ring 800 that slide towards each other.

[0066] Specifically, during the process of gear 700 and gear ring 800 moving towards each other in the axial direction and then sliding into meshing, the chamfered inclined surfaces of the two parts can guide the teeth of gear 700 to smoothly slide into the corresponding meshing position of gear ring 800, avoiding tooth collision due to tooth overlap of the two parts, preventing the teeth of gear 700 and gear ring 800 from breaking, and increasing the service life of gear 700 and gear ring 800.

[0067] Furthermore, in some embodiments, each first tooth 710 has two third chamfers 711 at its end, which are symmetrically distributed along the central axis of the first tooth 710. Each second tooth 810 has two fourth chamfers 811 at its end, which are also symmetrically distributed along the central axis of the second tooth 810. This ensures that the third chamfers 711 and fourth chamfers 811 can act as guides regardless of which side the first tooth 710 and the second tooth 810 come into contact with each other. The third chamfers 711 extend along the outer peripheral wall edge of the gear 700 to connect adjacent third chamfers 711, and the fourth chamfers 811 extend along the inner peripheral wall edge of the gear ring 800 to connect adjacent fourth chamfers 811. By increasing the guiding area, the first tooth 710 of the gear 700 can slide more smoothly into the corresponding meshing position of the gear ring 800.

[0068] Furthermore, in some embodiments, a circular boss 720 is provided at one end of the gear 700 that slides toward the gear ring 800. The circular boss 720 is arranged coaxially with the gear 700, and a plurality of evenly distributed third teeth 730 are provided on the outer peripheral wall of the circular boss 720, so that after meshing with the gear ring 800, the circular boss 720 can cooperate with other parts to perform meshing motion.

[0069] In this embodiment of the invention, the connector can be a clip or a plate of other shapes, and the connection method can be a snap fastener, screw fastening or welding, etc., which will not be described in detail here.

[0070] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A gear mold, characterized in that, include: The first upper punch mechanism includes a first upper punch seat and a first outer upper punch. The first upper punch seat is fixedly connected to the first outer upper punch, and a third through hole extending in the vertical direction is provided in the middle of the first outer upper punch. The first lower punch mechanism includes a first lower mandrel and a first outer lower punch. The lower end of the first lower mandrel is fixedly connected to a first mandrel base. The first mandrel base is connected to a first cylinder that pushes and resets the first lower mandrel. The first outer lower punch is fitted on the outer side of the first lower mandrel. The first lower mandrel and the first outer lower punch can move relative to each other. The first outer lower punch is fixedly connected to a first outer lower punch seat. The first outer lower punch seat is mounted on a gear mold support. The movement of the first outer lower punch seat is controlled by the gear mold support, thereby driving the first outer lower punch to move. The first mold includes a first mold base and a first mold core. The first mold base is located between the first upper punch mechanism and the first lower punch mechanism. The first mold base is fixed on the gear mold support. The first mold core is provided inside the first mold base. The first mold core has a first through hole in the middle for the first outer upper punch and the first lower punch mechanism to pass through. The first outer upper punch, the first mold core, the first lower mandrel and the first outer lower punch can cooperate to form a first forming cavity. The inner wall of the first mold core is provided with a plurality of first tooth grooves evenly distributed around its circumference. The first tooth grooves are located in the first forming cavity. The ends of the first tooth grooves are provided with a first chamfer. The first lower punch mechanism further includes a first inner lower punch, the first inner lower punch is fitted on the outer side of the first lower mandrel, and the first outer lower punch is fitted on the outer side of the first inner lower punch. The first outer lower punch, the first inner lower punch, and the first lower mandrel can move relative to each other. The first inner lower punch, the first outer lower punch, and the first lower mandrel can cooperate to form a boss forming cavity. The boss forming cavity is connected to the first forming cavity and is located directly below the first forming cavity. The inner wall of the first outer lower punch is evenly provided with a plurality of second tooth grooves, and the second tooth grooves are located in the boss forming cavity. Before filling with powder, the first cylinder is continuously ventilated so that the first lower core rod moves upward to be level with the end face of the first mold core. The first outer lower punch and the first inner lower punch form a cavity with the first mold core under the control of the gear mold support. During the powder filling process, the first cylinder is continuously ventilated, and the first lower core rod remains stationary. After the powder filling is completed, the first upper punch mechanism moves downward under the control of the gear mold support, and cooperates with the first mold core, the first lower core rod, the first outer lower punch and the first inner lower punch to form a cavity; During the pressing process, the upper end face of the first lower core rod is kept horizontal with the upper end face of the first mold core, and the first outer upper punch moves downward so that the upper end of the first lower core rod is inserted into the third through hole. After pressing is completed, the first upper punch moves upward under the control of the gear mold support, the first outer lower punch remains stationary, the first middle mold moves downward under the control of the gear mold support until the gear part is completely removed from the first middle mold, and then the first inner lower punch moves upward under the control of the gear mold support, thereby ejecting the gear part to achieve demolding.

2. The gear mold according to claim 1, characterized in that, Each of the first tooth grooves has two first chamfers at its end, and the two first chamfers are symmetrically distributed along the central axis of the first tooth groove.

3. A gear and gear ring assembly, comprising a gear and a gear ring, wherein the gear is capable of meshing with the gear ring and sliding relative to it axially, characterized in that, The gear is manufactured using the gear mold as described in claim 1 or 2, and the gear ring is manufactured using a gear ring mold. The gear ring mold includes a second upper punch mechanism, a second lower punch mechanism, and a second middle mold. The second upper punch mechanism includes a second upper punch seat, a second outer upper punch, and a first inner upper punch. The second upper punch seat is fixedly connected to the second outer upper punch and is connected to the gear ring mold support. The first inner upper punch passes through the middle of the second outer upper punch. A forming part is provided at the lower part of the first inner upper punch. A plurality of third tooth grooves are evenly distributed around the outer wall of the forming part. Two second chamfers are provided at the ends of the third tooth grooves. The two second chamfers are symmetrically distributed along the central axis of the third tooth groove. The second lower punch mechanism includes a second lower mandrel and a second outer lower punch. The lower end of the second lower mandrel is fixedly connected to a second mandrel base. The second mandrel base is connected to a second cylinder that pushes and resets the second lower mandrel. The second outer lower punch is fitted on the outer side of the second lower mandrel. The second lower mandrel and the second outer lower punch can move relative to each other. The second outer lower punch is fixedly connected to a second outer lower punch seat. The second outer lower punch seat is installed on the gear ring mold support. The movement of the second outer lower punch seat is controlled by the gear ring mold support, thereby driving the movement of the second outer lower punch. The second mold includes a second mold base and a second mold core. The second mold base is located between the second upper punch mechanism and the second lower punch mechanism. The second mold core is disposed inside the second mold base. The middle part of the second mold core is provided with a second through hole for the second outer upper punch, the first inner upper punch and the second lower punch mechanism to pass through. The second outer upper punch, the first inner upper punch, the second mold core, the second lower mandrel and the second outer lower punch can cooperate to form a second molding cavity. The molding part can be inserted into the second molding cavity. Before filling with powder, the second cylinder is continuously ventilated, causing the second lower core rod to move upward until it is level with the end face of the second mold core. Under the control of the gear ring mold support, the second outer lower punch forms a cavity with the second mold core. During the powder filling process, the second cylinder is continuously ventilated, and the second lower core rod remains stationary; After the powder filling is completed, the second upper punch mechanism moves downward under the control of the toothed mold support, and cooperates with the second mold core, the second lower core rod and the second outer lower punch to form the cavity; During the pressing process, the downward pressure of the second upper punch is greater than the upward pressure of the second cylinder, so as to force the forming part to contact the second lower mandrel and move downward together. After pressing is completed, the second upper punch mechanism moves upward under the control of the gear ring mold support, and the second middle mold moves downward under the control of the gear ring mold support until the gear ring part is completely removed from the second middle mold. Then the gear ring part fitted on the second outer lower punch is taken out to achieve demolding. The outer peripheral wall of the gear is provided with a plurality of first teeth evenly distributed, and the inner peripheral wall of the gear ring is provided with a plurality of second teeth evenly distributed. One end of the first teeth is provided with a third chamfer, and one end of the second teeth is provided with a fourth chamfer. The third chamfer and the fourth chamfer are arranged at the opposite ends of the gear and the gear ring that slide towards each other.

4. The gear and gear ring assembly according to claim 3, characterized in that, Each of the first teeth has two third chamfers at its end, and the two third chamfers are symmetrically distributed along the central axis of the first tooth. Each of the second teeth has two fourth chamfers at its end, and the two fourth chamfers are symmetrically distributed along the central axis of the second tooth.

5. The gear and gear ring assembly according to claim 4, characterized in that, The third chamfer extends along the outer peripheral wall edge of the gear to connect with the adjacent third chamfer, and the fourth chamfer extends along the inner peripheral wall edge of the gear ring to connect with the adjacent fourth chamfer.

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