Two-stage driving lifting system and additive manufacturing equipment

Abstract

The utility model discloses a two-stage driving lifting system which comprises a first-stage lifting driving mechanism and a second-stage lifting driving mechanism. The first-stage lifting driving mechanism comprises a first-stage base, a first-stage linear movement driving assembly, a first-stage bearing platform and a first-stage driving sliding plate. The second-stage lifting driving mechanism comprises a second-stage linear movement driving assembly, a second-stage bearing platform and a second-stage base. The first-stage driving sliding plate is connected with the first-stage base through the first-stage linear movement driving assembly, and the first-stage bearing platform is connected with the first-stage driving sliding plate; the second-stage base is located above the first-stage bearing platform and connected with the first-stage bearing platform. The second-stage bearing platform is connected with the second-stage base through a second-stage linear movement driving assembly. The utility model further discloses additive manufacturing equipment which comprises the two-stage driving lifting system, the height of the equipment can be greatly reduced under the condition that the forming height is not changed, and the problem that the height of a large additive equipment plant is limited is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of additive manufacturing, and specifically relates to a two-stage drive lifting system and additive manufacturing equipment. Background Art

[0002] Additive manufacturing technology is based on 3D CAD model data and is manufactured layer by layer by adding materials. It is based on the computer 3D design model, and uses software layered discrete and CNC forming system to stack materials layer by layer using high-energy beams, and finally stack and form to produce physical products. In order to ensure good metal powder sealing, the forming cylinder of existing additive manufacturing equipment generally adopts a piston lifting mechanism, that is, the forming platform is driven up and down by a lead screw from the bottom of the forming platform. Therefore, the height of the forming cylinder is at least twice the forming height. With the continuous expansion of the application of additive manufacturing technology, the market has higher and higher requirements for the forming height of equipment. Under the existing forming cylinder drive lifting system structure, the equipment height is already 7 or 8 meters high. The existing plant for equipment installation often needs to be modified because it cannot meet the installation height requirements, and the modification cost is high. If the side opening of the forming cylinder is adopted, the height of the equipment can indeed be greatly reduced, but the opening on the side of the cylinder is easy to leak powder, the equipment maintenance frequency is high, and the strength of the forming cylinder is also greatly affected. Utility Model Content

[0003] The purpose of the utility model is to overcome the shortcomings of the prior art and provide a two-stage drive lifting system, which can ensure that the equipment height is greatly reduced while the forming height remains unchanged, thereby solving the problem of limited height of large-scale additive equipment plants. In addition, there is no need to open an opening on the side of the forming cylinder, and there is no need to worry about powder leakage from the cylinder wall and deformation of the cylinder wall caused by insufficient strength of the forming cylinder.

[0004] The specific technical solutions adopted by the utility model are as follows:

[0005] A two-stage drive lifting system, comprising a primary lifting drive mechanism and a secondary lifting drive mechanism; the primary lifting drive mechanism comprises a primary base, a primary linear motion drive assembly, a primary bearing platform and a primary driving slide; the secondary lifting drive mechanism comprises a secondary linear motion drive assembly, a secondary bearing platform and a secondary base;

[0006] The first-level driving slide is connected to the first-level base through the first-level linear motion driving assembly, the first-level driving slide can move up and down relative to the first-level base, and the first-level bearing platform is connected to the first-level driving slide;

[0007] The secondary base is located above the primary bearing platform and is connected to the primary bearing platform; the secondary bearing platform is located above the secondary base and is connected to the secondary base via the secondary linear motion drive assembly; the secondary bearing platform can perform lifting and lowering movements relative to the secondary base.

[0008] Furthermore, the number of the first-level linear motion drive components and the first-level drive slides are both two, each of the first-level linear motion drive components is correspondingly equipped with one first-level drive slide, and the two first-level drive slides are both connected to the first-level bearing platform.

[0009] Furthermore, the first-level linear motion drive assembly includes a first-level drive motor, a first-level screw and a first-level nut, the first-level drive motor is fixedly mounted on the first-level base; the first-level screw is rotatably mounted on the first-level base, and the first-level screw is connected to the output shaft of the first-level drive motor, the first-level nut is fixedly mounted on the first-level drive skateboard, and the first-level screw passes through the first-level nut and is threadedly connected to the first-level nut.

[0010] Furthermore, the two-stage drive lifting system also includes a first-stage balancing oil cylinder, a fixed end of the first-stage balancing oil cylinder is installed on the first-stage base, and a telescopic end of the first-stage balancing oil cylinder is connected to the first-stage driving slide plate.

[0011] Furthermore, the secondary linear motion drive assembly includes a secondary drive motor, a secondary screw rod, a secondary nut and a transmission assembly, the secondary drive motor is fixedly mounted on the secondary base, the secondary nut is rotatably mounted on the secondary base, the secondary screw rod passes through the secondary nut and is threadedly connected to the secondary nut, and the secondary screw rod is connected to the secondary bearing platform, and the output shaft of the secondary drive motor is connected to the secondary nut through the transmission assembly.

[0012] Furthermore, the transmission assembly includes a driving gear and a driven gear, the driving gear is mounted on the output shaft of the secondary drive motor, the driven gear is mounted on the secondary nut, and the driving gear is meshed with the driven gear.

[0013] Furthermore, the secondary linear motion drive assembly includes a secondary drive motor, a secondary screw, a secondary nut and a sliding sleeve, the secondary drive motor is fixedly installed on the primary bearing platform, the secondary screw is rotatably installed on the secondary base, and the secondary screw is connected to the output shaft of the secondary drive motor; the secondary nut is fixedly installed on the sliding sleeve, the secondary screw passes through the secondary nut and is threadedly connected to the secondary nut, and the sliding sleeve is connected to the secondary bearing platform after passing through the secondary base; the number of the secondary drive motor, the secondary screw and the secondary nut 224 are all two, each of the secondary drive motors is correspondingly equipped with one secondary screw and a secondary nut 224, and the two secondary screws are symmetrically arranged relative to the vertical center line of the sliding sleeve.

[0014] Furthermore, the two-stage drive lifting system also includes a secondary balancing oil cylinder, a fixed end of the secondary balancing oil cylinder is installed on the secondary base, and a telescopic end of the secondary balancing oil cylinder is connected to the secondary bearing platform.

[0015] An additive manufacturing device includes the two-stage drive lifting system, and also includes a forming cylinder and a piston. The forming cylinder is located above the primary base and connected to the primary base, the piston is located in the forming cylinder, and the piston is located above the secondary support platform and connected to the secondary support platform. When the two-stage drive lifting system rises, the secondary lifting drive mechanism extends into the forming cylinder.

[0016] The beneficial effects of the utility model are as follows: the utility model adopts a two-stage drive lifting system consisting of a primary lifting drive mechanism and a secondary lifting drive mechanism. Under the condition that the forming height remains unchanged, the total height of the equipment can be greatly reduced. Compared with a single-stage drive lifting system with the same forming height, the two-stage drive lifting system of the utility model can reduce the total height of the equipment to half of its forming height, and there is no need to open a notch on the side of the forming cylinder, and there is no need to worry about cylinder wall deformation caused by powder leakage and insufficient strength of the forming cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the structure of the first embodiment of the utility model;

[0019] Figure 2 for Figure 1 AA section view;

[0020] Figure 3 for Figure 1 The partial schematic diagram of the corresponding first-level lifting drive mechanism;

[0021] Figure 4 for Figure 1 The partial schematic diagram of the corresponding secondary lifting drive mechanism;

[0022] Figure 5 This is a schematic diagram of the structure of the second embodiment of the present utility model;

[0023] Figure 6 for Figure 5 BB cross-sectional view.

[0024] The above reference numerals:

[0025] 1. Primary lifting drive mechanism; 10. Primary base; 11. Primary driving slide plate; 12. Primary bearing platform; 13. Primary linear motion drive assembly; 130. Primary driving motor; 131. Primary screw rod; 132. Primary nut; 133. Primary motor seat; 134. Primary coupling; 2. Secondary lifting drive mechanism; 20. Secondary base; 21. Secondary bearing platform; 22. Secondary linear motion drive assembly; 220. Secondary driving motor; 221. Secondary screw rod; 222. Driving gear; 223. Driven gear; 224. Secondary nut; 225. Sleeve; 226. Secondary motor seat; 227. Secondary coupling; 3. Secondary balancing cylinder; 4. Forming cylinder; 5. Piston; 6. Primary balancing cylinder. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively with reference to the accompanying drawings. The accompanying drawings show preferred embodiments of the present invention.

[0027] like Figure 1-Figure 6 As shown, a two-stage drive lifting system provided in this embodiment includes a first-stage lifting drive mechanism 1 and a second-stage lifting drive mechanism 2; the first-stage lifting drive mechanism 1 includes a first-stage base 10, a first-stage linear motion drive component 13, a first-stage bearing platform 12 and a first-stage driving slide 11; the second-stage lifting drive mechanism 2 includes a second-stage linear motion drive component 22, a second-stage bearing platform 21 and a second-stage base 20.

[0028] The first-level driving skateboard 11 is connected to the first-level base 10 through the first-level linear motion driving component 13, and the first-level driving skateboard 11 can perform lifting and lowering movements relative to the first-level base 10, and the first-level supporting platform 12 is connected to the first-level driving skateboard 11; the second-level base 20 is located above the first-level supporting platform 12 and is connected to the first-level supporting platform 12; the second-level supporting platform 21 is located above the second-level base 20, and the second-level supporting platform 21 is connected to the second-level base 20 through the second-level linear motion driving component 22; the second-level supporting platform 21 can perform lifting and lowering movements relative to the second-level base 20.

[0029] In this embodiment, the first-level linear motion drive assembly 13, the first-level bearing platform 12 and the first-level driving slide plate 11 are preferably located in the first-level base 10, and the structure is compact, which effectively reduces the overall height of the first-level lifting drive mechanism 1 after it is retracted. In this embodiment, when the second-level lifting drive mechanism 2 descends, it descends into the first-level base 10, thereby effectively reducing the overall height of the two-stage drive lifting system after it is retracted.

[0030] The two-stage drive lifting system of this embodiment is used for lifting and lowering the piston 5 in the forming cylinder 4 of the additive manufacturing equipment. Therefore, this embodiment also provides an additive manufacturing equipment, including the two-stage drive lifting system, and also including a forming cylinder 4 and a piston 5. The forming cylinder 4 is located above the primary base 10 and connected to the primary base 10, and the piston 5 is located in the forming cylinder 4, and the piston 5 is located above the secondary support platform 21 and connected to the secondary support platform 21. When the two-stage drive lifting system rises, the secondary lifting drive mechanism 2 extends into the forming cylinder 4. Of course, the additive manufacturing equipment also includes other conventional configurations such as a powder spreading mechanism and a substrate, which will not be elaborated in detail. In this embodiment, the forming cylinder 4 is installed above the primary base 10, and the forming cylinder 4 is a complete closed structure, and there is no need to open the side of the forming cylinder 4 for the drive system to move up and down.

[0031] When the two-stage drive lifting system of this embodiment is lifted, the first-stage lifting drive mechanism 1 and the second-stage lifting drive mechanism 2 each complete a part of the lifting stroke of the piston 5, so that the overall height of the equipment can be greatly reduced while the forming height remains unchanged. Compared with a single-stage drive lifting system having the same forming height, the two-stage drive lifting system of this embodiment can reduce the overall height of the equipment to half of its forming height, and there is no need to open a notch on the side of the forming cylinder 4, and there is no need to worry about powder leakage from the cylinder wall and deformation of the cylinder wall caused by insufficient strength of the forming cylinder 4.

[0032] When the two-stage drive lifting system of this embodiment is working, the first-stage linear motion drive assembly 13 drives the first-stage drive slide 11 to do lifting motion. Since the first-stage drive slide 11 is connected to the second-stage base 20 via the first-stage bearing platform 12, the lifting of the first-stage drive slide 11 will synchronously drive the second-stage lifting drive mechanism 2 to do lifting motion. When the second-stage lifting drive mechanism 2 is lifted or lowered alone, the second-stage linear motion drive assembly 22 drives the second-stage bearing platform 21 to do lifting motion.

[0033] When the two-stage lifting drive system of this embodiment is used for additive manufacturing equipment, its specific working process is as follows:

[0034] (1) The substrate is fixedly mounted above the piston 5, the second-stage lifting drive mechanism 1 drives the piston 5 to rise to the highest point of its stroke, and then the second-stage lifting drive mechanism 2 drives the piston 5 to continue to rise, and finally the upper surface of the substrate is flush with the working plane of the equipment;

[0035] (2) The powder spreading mechanism spreads a layer of powder on the surface of the substrate, and the energy beam scans the powder layer;

[0036] (3) After the scanning is completed, the secondary lifting drive mechanism 2 drives the piston 5 to descend by a powder layer thickness;

[0037] (4) Repeat steps (2) and (3) until the forming of the parts within the travel range of the secondary lifting drive mechanism 2 is completed, at which point the energy beam has scanned the powder layer but the piston 5 has not yet descended;

[0038] (5) The first-stage lifting drive mechanism 1 then takes over and drives the piston 5 to descend by a powder layer thickness;

[0039] (6) The powder spreading mechanism spreads a layer of powder on the surface of the substrate, and the energy beam scans the powder layer;

[0040] (7) Repeat steps (5) and (6) until the entire part is formed.

[0041] In this embodiment, preferably, the number of the primary linear motion drive assembly 13 and the primary drive slide 11 are both two, each primary linear motion drive assembly 13 is equipped with one primary drive slide 11, and the two primary drive slides 11 are connected to the primary bearing platform 12. The lifting drive is performed by two primary linear motion drive assemblies 13, which has good rigidity and good motion stability.

[0042] In this embodiment, the first-level linear motion drive assembly 13 preferably includes a first-level drive motor 130, a first-level screw rod 131 and a first-level nut 132. The first-level drive motor 130 is fixedly mounted on the first-level base 10. Specifically, the first-level drive motor 130 is fixedly mounted on the first-level base 10 through a first-level motor seat 133. The first-level screw rod 131 is rotatably mounted on the first-level base 10, and the first-level screw rod 131 is connected to the output shaft of the first-level drive motor 130. Specifically, the first-level screw rod 131 is connected to the output shaft of the first-level drive motor 130 through a first-level coupling 134. The first-level nut 132 is fixedly mounted on the first-level drive slide 11, and the first-level screw rod 131 passes through the first-level nut 132 and is threadedly connected to the first-level nut 132. Therefore, the first-level lifting drive mechanism 1 of this embodiment adopts a double screw synchronous drive, which not only has good rigidity and good motion stability, but also has high precision.

[0043] When the primary linear motion drive assembly 13 of this embodiment is working, the primary drive motor 130 is started to drive the primary screw rod 131 to rotate. Since the primary screw rod 131 and the primary nut 132 are spirally driven, the rotation of the primary screw rod 131 will drive the primary nut 132 to do linear motion, and the primary nut 132 is fixedly installed on the primary drive slide 11, so the rotation of the primary screw rod 131 will drive the primary nut 132 and the primary drive slide 11 to do lifting motion.

[0044] In the present embodiment, the two-stage drive lifting system further comprises a first-stage balancing oil cylinder 6, the fixed end of which is mounted on the first-stage base 10, and the telescopic end of which is connected to the first-stage driving slide 11. In the present embodiment, the number of the first-stage balancing oil cylinders 6 is two, and each first-stage driving slide 11 is equipped with one first-stage balancing oil cylinder 6.

[0045] In this embodiment, the first-level balancing oil cylinder 6 is used to balance the weight of the first-level driving slide 11, the first-level bearing platform 12, the second-level lifting drive mechanism 2 and the piston 5, and offset the weight of the moving parts themselves when unloaded. When the first-level driving slide 11 and the first-level bearing platform 12 rise and fall, the first-level balancing oil cylinder 6 always gives the first-level driving slide 11 an upward pulling force, which balances the weight of the first-level driving slide 11, the first-level bearing platform 12, the second-level driving mechanism and the piston 5. Therefore, when the piston 5 is unloaded, the first-level driving motor 130 only needs to drive the operation of the first-level screw rod 131 without bearing the load of the other moving parts. The first-level driving motor 130 moves more smoothly, and the life of the first-level driving motor 130 and the first-level screw rod 131 is longer.

[0046] In this embodiment, preferably, the structures of the secondary linear motion drive assembly 22 are as follows:

[0047] The first one: See Figure 1 and 2 As shown, the secondary linear motion drive assembly 22 includes a secondary drive motor 220, a secondary screw rod 221, a secondary nut 224 and a transmission assembly. The secondary drive motor 220 is fixedly mounted on the secondary base 20. Specifically, the secondary drive motor 220 is fixedly mounted on the secondary base 20 through a motor seat (not shown in the figure); the secondary nut 224 is rotatably mounted on the secondary base 20, the secondary screw rod 221 passes through the secondary nut 224 and is threadedly connected to the secondary nut 224, and the secondary screw rod 221 is connected to the secondary bearing platform 21, and the output shaft of the secondary drive motor 220 is connected to the secondary nut 224 through the transmission assembly.

[0048] When this secondary linear motion drive component 22 is working, the secondary drive motor 220 is started, and the secondary nut 224 is driven to rotate through the transmission component. The secondary screw rod 221 and the secondary nut 224 are spirally transmitted. Since the secondary nut 224 is rotatably installed on the secondary base 20, and the secondary base 20 is connected to the primary supporting platform 12, the rotation of the secondary nut 224 will drive the secondary screw rod 221 to perform lifting movement relative to the secondary base 20, and the lifting and lowering of the secondary screw rod 221 will drive the secondary supporting platform 21 to lift and lower synchronously.

[0049] In this embodiment, the transmission assembly preferably includes a driving gear 222 and a driven gear 223, wherein the driving gear 222 is mounted on the output shaft of the secondary drive motor 220, and the driven gear 223 is mounted on the secondary nut 224, and the driving gear 222 is meshed with the driven gear 223. When the secondary drive motor 220 is started, the driving gear 222 is driven to rotate, and the driven gear 223 is mounted on the secondary nut 224, so the rotation of the driving gear 222 drives the driven gear 223 and the secondary nut 224 to rotate together.

[0050] Second: See Figure 3 and 4As shown, the secondary linear motion drive assembly 22 includes a secondary drive motor 220, a secondary screw rod 221, a secondary nut 224 and a sleeve 225. The secondary drive motor 220 is fixedly mounted on the primary bearing platform 12, and the secondary drive motor 220 is fixedly mounted on the primary bearing platform 12 through a secondary motor seat 226; the secondary screw rod 221 is rotatably mounted on the secondary base 20, and the secondary screw rod 221 is connected to the output shaft of the secondary drive motor 220. Specifically, the secondary screw rod 221 is connected to the output shaft of the secondary drive motor 220 through a secondary coupling 227. The secondary nut 224 is fixedly mounted on the sliding sleeve 225, the secondary screw rod 221 passes through the secondary nut 224 and is threadedly connected to the secondary nut 224, and the sliding sleeve 225 passes through the secondary base 20 and is connected to the secondary bearing platform 21; the number of the secondary driving motor 220, the secondary screw rod 221 and the secondary nut 224 is two, each of the secondary driving motor 220 is equipped with a secondary screw rod 221 and a secondary nut 224, and the two secondary screw rods 221 are symmetrically arranged relative to the vertical center line of the sliding sleeve 225. It is driven by two secondary screw rods 221, which can improve the overall rigidity of the two-stage lifting drive system, and has a significant effect in large-scale additive manufacturing equipment.

[0051] When this secondary linear motion drive component 22 is working, the secondary drive motor 220 is started, which will drive the secondary screw rod 221 to rotate on the secondary base 20. Since the secondary screw rod 221 and the secondary nut 224 are spirally driven, the rotation of the secondary screw rod 221 will drive the secondary nut 224 to move linearly, and the secondary nut 224 is fixedly installed on the sleeve 225. Therefore, the rotation of the secondary screw rod 221 will drive the secondary nut 224 and the sleeve 225 to move up and down relative to the secondary screw rod 221. The sleeve 225 is connected to the secondary lifting platform, so the lifting of the sleeve 225 will drive the secondary bearing platform 21 to rise and fall synchronously.

[0052] In this embodiment, the two-stage drive lifting system further comprises a secondary balancing oil cylinder 3, the fixed end of the secondary balancing oil cylinder 3 is mounted on the secondary base 20, and the telescopic end of the secondary balancing oil cylinder 3 is connected to the secondary bearing platform 21. Figure 1 and 2As shown, the secondary drive balance cylinder is used to balance the weight of the secondary bearing platform 21 and the piston 5. When the secondary drive bearing platform rises and falls, the secondary balance cylinder 3 always gives the secondary base 20 an upward pulling force, which balances the weight of the secondary bearing platform 21 and the piston 5. Therefore, when the piston 5 is in an unloaded state, the secondary drive motor 220 only needs to drive the operation of the secondary screw rod 221 without bearing the load of other moving parts. The secondary drive motor 220 moves more smoothly, and the service life of the secondary drive motor 220 and the secondary screw rod 221 is longer. See Figure 1 and 2 As shown, preferably, the number of the secondary balancing oil cylinders 3 is two, and the two secondary balancing oil cylinders 3 are symmetrically arranged relative to the secondary screw rod 221. Figure 5 and Figure 6 In the embodiment of the present invention, two secondary balancing cylinders 3 may also be provided, which are not shown in the figure.

[0053] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. The utility model may have various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A two-stage drive lifting system, characterized in that: The invention comprises a primary lifting drive mechanism (1) and a secondary lifting drive mechanism (2); the primary lifting drive mechanism (1) comprises a primary base (10), a primary linear motion drive component (13), a primary bearing platform (12) and a primary driving slide plate (11); the secondary lifting drive mechanism (2) comprises a secondary linear motion drive component (22), a secondary bearing platform (21) and a secondary base (20); The primary driving slide (11) is connected to the primary base (10) via the primary linear motion driving assembly (13); the primary driving slide (11) can move up and down relative to the primary base (10); and the primary bearing platform (12) is connected to the primary driving slide (11); The secondary base (20) is located above the primary bearing platform (12) and is connected to the primary bearing platform (12); the secondary bearing platform (21) is located above the secondary base (20), and the secondary bearing platform (21) is connected to the secondary base (20) via the secondary linear motion drive assembly (22); the secondary bearing platform (21) can perform lifting movement relative to the secondary base (20).

2. The two-stage drive lifting system according to claim 1, characterized in that: The number of the first-level linear motion drive components (13) and the first-level drive slides (11) are both two, each of the first-level linear motion drive components (13) is correspondingly equipped with one first-level drive slide (11), and the two first-level drive slides (11) are both connected to the first-level bearing platform (12).

3. The two-stage drive lifting system according to claim 2, characterized in that: The primary linear motion drive assembly (13) comprises a primary drive motor (130), a primary screw rod (131) and a primary nut (132); the primary drive motor (130) is fixedly mounted on the primary base (10); the primary screw rod (131) is rotatably mounted on the primary base (10), and the primary screw rod (131) is connected to the output shaft of the primary drive motor (130); the primary nut (132) is fixedly mounted on the primary drive slide plate (11), and the primary screw rod (131) passes through the primary nut (132) and is threadedly connected to the primary nut (132).

4. The method according to claim 3, characterized in that: The two-stage drive lifting system also includes a first-stage balancing oil cylinder (6), the fixed end of the first-stage balancing oil cylinder (6) is installed on the first-stage base (10), and the telescopic end of the first-stage balancing oil cylinder (6) is connected to the first-stage driving slide plate (11).

5. The two-stage drive lifting system according to claim 1, characterized in that: The secondary linear motion drive assembly (22) comprises a secondary drive motor (220), a secondary screw rod (221), a secondary nut (224) and a transmission assembly, wherein the secondary drive motor (220) is fixedly mounted on the secondary base (20), the secondary nut (224) is rotatably mounted on the secondary base (20), the secondary screw rod (221) passes through the secondary nut (224) and is threadedly connected to the secondary nut (224), and the secondary screw rod (221) is connected to the secondary bearing platform (21), and the output shaft of the secondary drive motor (220) is connected to the secondary nut (224) through the transmission assembly.

6. The two-stage drive lifting system according to claim 5, characterized in that: The transmission assembly comprises a driving gear (222) and a driven gear (223); the driving gear (222) is mounted on the output shaft of the secondary drive motor (220); the driven gear (223) is mounted on the secondary nut (224); and the driving gear (222) is meshed with the driven gear (223).

7. The two-stage drive lifting system according to claim 1, characterized in that: The secondary linear motion drive assembly (22) comprises a secondary drive motor (220), a secondary screw rod (221), a secondary nut (224) and a sliding sleeve (225); the secondary drive motor (220) is fixedly mounted on the primary bearing platform (12); the secondary screw rod (221) is rotatably mounted on the secondary base (20); and the secondary screw rod (221) is connected to the output shaft of the secondary drive motor (220); the secondary nut (224) is fixedly mounted on the sliding sleeve (225); the secondary screw rod (221) passes through the secondary nut (224) and is threadedly connected to the secondary nut (224); and the sliding sleeve (225) passes through the secondary base (20) and is connected to the secondary bearing platform (21); The number of the secondary drive motor (220), the secondary screw rod (221) and the secondary nut (224) is two, each of the secondary drive motors (220) is equipped with a corresponding secondary screw rod (221) and a secondary nut (224), and the two secondary screw rods (221) are symmetrically arranged relative to the vertical center line of the sliding sleeve (225).

8. The two-stage drive lifting system according to claim 5, characterized in that: The two-stage drive lifting system also includes a secondary balancing oil cylinder (3), the fixed end of the secondary balancing oil cylinder (3) is installed on the secondary base (20), and the telescopic end of the secondary balancing oil cylinder (3) is connected to the secondary bearing platform (21).

9. An additive manufacturing device, characterized in that: It includes the two-stage drive lifting system as described in any one of claims 1 to 8, and also includes a forming cylinder (4) and a piston (5), wherein the forming cylinder (4) is located above the primary base (10) and is connected to the primary base (10), the piston (5) is located in the forming cylinder (4), and the piston (5) is located above the secondary support platform (21) and is connected to the secondary support platform (21), and when the two-stage drive lifting system rises, the secondary lifting drive mechanism (2) extends into the forming cylinder (4).

Images