Master-slave gear type one-way particle material conveying 3D printing gear assembly and design method thereof

Abstract

The invention provides a driving-driven gear type one-way conveying particle type material 3D printing gear assembly and a design method thereof, and belongs to the technical field of 3D printing. A flow control assembly for meshing transmission of a driving gear and a driven gear is arranged in a storage shell, and the mathematical relation of the number of teeth, the rotating speed and the diameter is established through a gear transmission ratio calculation equation; an output matching equation is adopted to determine the inner diameter size of an output pipe, a containing groove depth optimization equation is matched to determine the gear embedding depth, the screw pitch of a conveying screw and parameters of a flow control assembly are coordinated through a screw pitch optimization equation, and a complete transmission chain from particle material conveying to liquid flow control is constructed. Accurate control over the rotating speed of the driven gear through rotating speed adjustment of the driving gear is achieved, the matching relation between the liquid conveying rate and the size of an output channel is guaranteed, and the technical problem that in the 3D printing particle material conveying process, liquid flow control precision is insufficient is solved.

Description

Technical Field

[0001] This invention belongs to the field of 3D printing technology, specifically, it relates to a master-slave gear type unidirectional conveying granular material 3D printing gear assembly and its design method. Background Technology

[0002] In the field of 3D printing technology, the molten delivery of granular materials is a crucial step in achieving precision molding. Traditional granular material delivery devices typically employ a single screw extrusion mechanism, where the screw rotation pushes the granular material to a heating zone for melting and output. In existing technologies, because the screw extrusion mechanism relies on single-stage transmission control, it is difficult to maintain a stable output flow rate of the molten liquid when the printing speed changes or the material viscosity fluctuates, resulting in uneven printed layer thickness. Existing flow control methods mainly achieve this by adjusting the screw speed or heating temperature, but this approach has a slow response time and limited control precision. Especially in applications requiring rapid changes in output flow rate, the single-stage transmission structure cannot provide a sufficient transmission ratio adjustment range, causing a mismatch between the liquid delivery rate and printing requirements. In other words, existing technologies suffer from insufficient precision in liquid flow control during the 3D printing granular material delivery process. Summary of the Invention

[0003] In view of this, the present invention provides a master-slave gear type unidirectional conveying granular material 3D printing gear assembly and its design method, which can solve the technical problem of insufficient liquid flow control accuracy in the conveying process of 3D printed granular materials in the prior art.

[0004] The present invention is implemented as follows: The first aspect of the present invention provides a master-slave gear type unidirectional conveying granular material 3D printing gear assembly, including a storage housing and a conveying assembly. The top of the storage housing and the bottom of the conveying assembly are connected through the storage housing. The conveying assembly is used to convey the liquid formed by melting the granular material into the storage housing. A flow control assembly is provided in the middle of the storage housing. The flow control assembly includes a driving gear and a driven gear, which are meshed together. The center of the driving gear is fixedly connected to a driving assembly. The driving assembly is used to drive the driving gear to rotate. The rotation of the driving gear drives the driven gear to rotate synchronously, pushing the liquid downwards through the gear surface. An output pipe is provided at the center of the bottom of the storage housing. The output pipe is used to discharge the liquid conveyed by the rotating flow control assembly. The transmission relationship between the driving gear and the driven gear is determined by a gear transmission ratio calculation equation, which determines the rotational speed and tooth tip circle diameter of the driven gear.

[0005] Among them, the driving gear and the driven gear are dual-type gear structures with the same tooth shape but different number of teeth. The outer diameter of the driving gear teeth is smaller than that of the driven gear teeth, and the number of teeth of the driving gear is smaller than that of the driven gear.

[0006] The tooth profiles of both the driving gear and the driven gear adopt an involute tooth profile design, and the ratio of the root circle diameter of the driving gear to the root circle diameter of the driven gear is 1:1.5 to 1:2.5.

[0007] The drive assembly includes a rotating rod and a fixed rod. The rotating rod is fixedly connected to the geometric center of the drive gear and is used to drive the drive gear to rotate around its geometric center axis. The fixed rod is fixed at the geometric center of the driven gear.

[0008] The central axis of the rotating rod is perpendicular to the plane of the driving gear, the central axis of the fixed rod is perpendicular to the plane of the driven gear, and the outer cylindrical diameter of the rotating rod is larger than the outer cylindrical diameter of the fixed rod.

[0009] The rotating rod is made of stainless steel, and the fixed rod is made of alloy steel. The ratio of the length of the rotating rod to the height of the storage shell is 0.6 to 0.9.

[0010] One end of the rotating rod is connected to the power system of the 3D printer. The power system includes a drive motor and a transmission belt. The end of the rotating rod is provided with a keyway structure, and the inner side of the transmission belt is provided with a key tooth structure that cooperates with the keyway structure.

[0011] The depth of the keyway structure is 0.1 to 0.15 times the outer diameter of the rotating rod, and the transmission relationship between the driving gear and the driven gear satisfies the gear transmission ratio calculation equation.

[0012] The conveying component is a conveying screw, which is positioned above the storage housing. The ratio of the outer diameter of the spiral blades of the conveying screw to the inner diameter of the top opening of the storage housing is 0.85 to 0.95.

[0013] The storage housing includes a storage section and a fixing section. The storage section is located above the fixing section, and the storage section and the fixing section are integrally connected to form a seamless connection structure. The interior of the storage section and the fixing section forms a liquid storage chamber.

[0014] The inner wall surface of the storage cavity is coated with polytetrafluoroethylene. The outer wall of the storage part is cylindrical, and the outer wall of the fixing part is frustoconical. The cone angle of the fixing part is 15°~25°.

[0015] The flow control component is located on the side wall of the fixed part, and a receiving groove is provided on the side wall of the fixed part. Both the driving gear and the driven gear are partially embedded in the receiving groove, and the depth of the receiving groove is 0.4 to 0.6 times the tooth height of the driving gear.

[0016] The ratio of the volume of the storage section to the volume of the fixed section is 3:1 to 5:1. An opening is provided in the storage section near the fixed section, and the ratio of the area of ​​the opening to the area of ​​the bottom surface of the storage section is 0.3 to 0.5.

[0017] The dimensional relationship between the inner diameter of the output tube and the tip circle diameter of the drive gear satisfies the output matching equation. The output tube is made of stainless steel and the wall thickness of the output tube is 0.08 to 0.12 times the inner diameter of the output tube.

[0018] The relationship between the center distance between the driving gear and the driven gear and the tip circle diameter of the driving gear and the driven gear satisfies the center distance calculation equation. The tooth surface of the driving gear is carburized and quenched, and the tooth surface of the driven gear is nitrided.

[0019] The rotating rod and the driving gear are connected by an interference fit. The interference between the outer diameter of the end of the rotating rod and the inner diameter of the center hole of the driving gear is 0.001 to 0.003 times the outer diameter of the end of the rotating rod. The fixed rod and the driven gear are connected by a pin.

[0020] The second aspect of this invention provides a design method for a 3D-printed gear assembly for unidirectional conveying of granular materials using a master-slave gear system, comprising the following steps: constructing a master-slave gear unidirectional conveying control framework, determining the meshing transmission relationship between the driving gear and the driven gear, setting the number of teeth on the driving gear to be 12 to 18 teeth and the number of teeth on the driven gear to be 24 to 36 teeth, and setting the ratio of the root circle diameter of the driving gear to the root circle diameter of the driven gear to be 1:1.5 to 1:2.5; establishing a game-theoretic optimization model for gear transmission parameters, wherein the upper-level model, with the goal of maximizing liquid conveying efficiency, inputs the number of teeth on the driving gear, the number of teeth on the driven gear, and the rotational speed of the driving gear, while the lower-level model, with the goal of maximizing gear meshing stability, inputs the tip circle diameter of the driving gear and the tip circle diameter of the driven gear, and the two models are coupled through the gear transmission ratio; collecting experimental data to determine the output matching equation coefficients, the cavity depth optimization equation coefficients, and the pitch optimization equation coefficients; and adjusting the gear transmission parameters according to the calculation results of the game-theoretic optimization model for gear transmission parameters.

[0021] The upper-level model objective function is used to calculate the liquid transport efficiency index based on the number of teeth of the driving gear, the number of teeth of the driven gear, the rotational speed of the driving gear, the tip circle diameter of the driving gear, and the tip circle diameter of the driven gear. The lower-level model objective function is used to calculate the gear meshing stability index based on the tip circle diameter of the driving gear, the tip circle diameter of the driven gear, the gear pressure angle, and the gear transmission ratio.

[0022] Specifically, when the deviation between the liquid transport efficiency index calculated by the upper-level model and the preset transport efficiency threshold is greater than 8%, the rotation speed of the drive gear is increased by 5% to 15%; when the gear meshing stability index calculated by the lower-level model is lower than 0.85, the center distance between the drive gear and the driven gear is reduced by 3% to 10%.

[0023] This invention constructs a unidirectional liquid delivery control mechanism driven by a master-slave gear system. A flow control component with meshing drive and driven gears is installed inside the storage housing, precisely adjusting the liquid delivery rate using the gear ratio. The drive and driven gears employ different tooth counts, and the rotational speed of the driven gear is precisely controlled through a gear ratio calculation equation. Simultaneously, an output matching equation determines the inner diameter of the output pipe, ensuring a match between the liquid output flow rate and the gear transmission parameters, avoiding the limited adjustment range of single-stage transmission structures. An optimized formula for the receiving tank depth determines the gear embedding depth based on gear geometry and the output pipe size, ensuring the gear's driving force on the liquid is fully utilized. An optimized formula for the screw pitch coordinates the cooperation between the delivery screw and the flow control component, achieving synchronous optimization of granular material melting and delivery with liquid flow control. In summary, this invention solves the technical problem of insufficient liquid flow control precision during 3D printing granular material delivery mentioned in the background art. Attached Figure Description

[0024] Figure 1 This is a front structural diagram of a master-slave gear type unidirectional conveying granular material 3D printed gear assembly;

[0025] Figure 2 This is a schematic diagram of the flow control component.

[0026] Figure 3 This is a schematic diagram of the conveying component.

[0027] The attached diagram lists the components represented by each number as follows:

[0028] 1. Storage housing; 11. Storage section; 12. Fixing section; 2. Flow control assembly; 21. Drive gear; 22. Driven gear; 3. Drive assembly; 31. Rotating rod; 32. Fixing rod; 4. Output pipe; 5. Conveying assembly. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0030] The utility model patent with application number 202620089372.4, entitled "A 3D printer extrusion control component with dual-type gears", proposes a structure for a forming control component using master and slave gears. This invention makes more detailed adjustments and expansions based on the above-mentioned utility model patent. The specific structure and design are described as follows.

[0031] like Figures 1-3 The diagram shown is a schematic diagram of a master-slave gear type unidirectional conveying granular material 3D printing gear assembly provided by the first aspect of the present invention. It includes a storage shell 1 and a conveying assembly 5. The top of the storage shell is connected to the bottom of the conveying assembly. The conveying assembly is used to convey the liquid formed by melting the granular material into the interior of the storage shell. A flow control assembly 2 is provided at the middle position of the storage shell. The center position of the flow control assembly is fixedly connected to a driving assembly 3. The driving assembly is used to drive the flow control assembly to rotate. An output pipe 4 is provided at the center position of the bottom of the storage shell. The output pipe is used to discharge the liquid conveyed by the rotating flow control assembly.

[0032] In this invention, a unidirectional liquid transport control concept based on master-slave gear engagement is constructed. The flow control component includes a driving gear 21 and a driven gear 22. The driving gear and the driven gear are meshed and connected, and the rotation drives the liquid to be transported downwards by the flow control component. The driving gear and the driven gear are dual-type gear structures with the same tooth profile but different tooth numbers. The outer diameter of the driving gear teeth is smaller than that of the driven gear teeth, and the number of teeth of the driving gear is smaller than that of the driven gear. The tooth profiles of both the driving gear and the driven gear adopt an involute tooth profile design. The root circle diameter of the driving gear is smaller than that of the driven gear. The ratio of the root circle diameter of the driven gear is in the range of 1:1.5 to 1:2.5. This ratio is set to ensure a stable contact area between the two gears during meshing. When the ratio of the root circle diameter of the driving gear to that of the driven gear is less than 1:1.5, the root strength of the driven gear is insufficient, which may lead to root fracture under high-speed operation. When the ratio of the root circle diameter of the driving gear to that of the driven gear is greater than 1:2.5, the center distance between the driving gear and the driven gear is too large, which may increase the overall volume of the storage housing and reduce space utilization.

[0033] The drive assembly includes a rotating rod 31 and a fixed rod 32. The rotating rod is fixedly connected to the geometric center of the driving gear and drives the driving gear to rotate around its geometric center axis. The fixed rod is fixed to the geometric center of the driven gear and provides support for the driven gear as it follows the rotation of the driving gear. The central axis of the rotating rod is perpendicular to the plane containing the driving gear, and the central axis of the fixed rod is perpendicular to the plane containing the driven gear. The outer cylindrical diameter of the rotating rod is larger than that of the fixed rod. The rotating rod is made of stainless steel to withstand the driving torque. The fixing rod is made of alloy steel to provide support rigidity. The ratio of the length of the rotating rod to the height of the storage housing is in the range of 0.6 to 0.9. This ratio ensures that the rotating rod has sufficient installation space when driving the drive gear. When the ratio is less than 0.6, the insufficient installation depth of the rotating rod will result in a shallow meshing depth between the drive gear and the driven gear, thus reducing transmission stability. When the ratio is greater than 0.9, the rotating rod will interfere with the bottom of the storage housing, affecting the normal operation of the output tube.

[0034] One end of the rotating rod is connected to the power system of the 3D printer. The power system includes a drive motor and a transmission belt. The output shaft of the drive motor is fixedly connected to the end of the rotating rod via the transmission belt. The end of the rotating rod is provided with a keyway structure. The inner side of the transmission belt is provided with a key tooth structure that mates with the keyway structure. The depth of the keyway structure is 0.1 to 0.15 times the outer diameter of the rotating rod. The depth of the keyway structure is set to ensure the connection strength between the transmission belt and the rotating rod. When the depth of the keyway structure is less than 0.1 times the outer diameter of the rotating rod, the meshing depth between the key tooth structure and the keyway structure is insufficient, which will cause slippage under high-speed rotation. When the depth of the keyway structure is greater than 0.15 times the outer diameter of the rotating rod, the keyway structure will weaken the torsional strength of the rotating rod, thus causing it to break under large torque.

[0035] The velocity of the liquid output by the flow control component is adjusted by regulating the rotational speed of the driving gear and the tooth ratio between the driving gear and the driven gear. The transmission relationship between the driving gear and the driven gear satisfies the gear transmission ratio calculation equation, which is as follows: The gear ratio calculation equation is used to calculate the rotational speed and tip circle diameter of the driven gear based on the number of teeth of the driving gear, the number of teeth of the driven gear, the rotational speed of the driving gear, and the tip circle diameter of the driving gear. The input includes the number of teeth of the driving gear. Number of teeth on the driven gear Rotational speed of the drive gear and the tip circle diameter of the driving gear The output is the rotational speed of the driven gear. and the tip circle diameter of the driven gear ,in This is the gear transmission ratio.

[0036] The conveying assembly is a conveying screw, which is positioned above the storage housing. The ratio of the outer diameter of the screw's helical blades to the inner diameter of the top opening of the storage housing is in the range of 0.85 to 0.95. This ratio ensures that the granular material can smoothly enter the storage housing while maintaining a tight seal during the melting and conveying process. When the ratio is less than 0.85, the excessive gap between the screw's helical blades and the top opening of the storage housing can cause backflow of the molten liquid, reducing conveying efficiency. Conversely, when the ratio is greater than 0.95, the insufficient gap between the screw's helical blades and the top opening of the storage housing can increase frictional resistance, thereby increasing drive power consumption.

[0037] The storage housing includes a storage section 11 and a fixing section 12. The storage section is located above the fixing section and is integrally connected to the fixing section to form a seamless connection structure. The interior of the storage section and the fixing section forms a liquid storage chamber. The inner wall surface of the storage chamber is treated with polytetrafluoroethylene coating to reduce liquid flow resistance. The outer wall of the storage section is cylindrical, and the outer wall of the fixing section is frustoconical. The diameter of the upper end face of the fixing section is equal to the diameter of the lower end face of the storage section, and the diameter of the lower end face of the fixing section is smaller than the diameter of the upper end face of the fixing section. The cone angle of the fixing section is in the range of 15° to 25°. The cone angle of the fixing section is set to guide the liquid to flow towards the flow control component. When the cone angle of the fixing section is less than 15°, the liquid flow speed inside the fixing section is too slow, which will cause the liquid to stagnate inside the fixing section and affect the output stability. When the cone angle of the fixing section is greater than 25°, the liquid flow speed inside the fixing section is too fast, which will cause the flow control component to be unable to deliver the liquid to the output pipe in time, resulting in liquid accumulation.

[0038] The flow control component is located on the side wall of the fixed part, and a receiving groove is formed on the side wall of the fixed part. Both the driving gear and the driven gear are partially embedded in the receiving groove. The depth of the receiving groove is 0.4 to 0.6 times the tooth height of the driving gear. The depth of the receiving groove is set to ensure that the driving gear and the driven gear maintain sufficient contact with the liquid during rotation. When the depth of the receiving groove is less than 0.4 times the tooth height of the driving gear, the insufficient embedding depth of the driving gear and the driven gear will weaken the driving force of the gear on the liquid, thereby reducing the liquid delivery efficiency. When the depth of the receiving groove is greater than 0.6 times the tooth height of the driving gear, the excessive embedding depth of the driving gear and the driven gear will cause interference between the gear and the bottom of the receiving groove, thereby hindering the normal rotation of the gear.

[0039] The volume of the storage section is larger than the volume of the fixed section, and the ratio of the volume of the storage section to the volume of the fixed section is in the range of 3:1 to 5:1. This ratio ensures sufficient liquid reserve within the storage chamber. When the ratio is less than 3:1, insufficient liquid reserve leads to frequent material replenishment during continuous printing, reducing efficiency. When the ratio is greater than 5:1, excessive storage volume increases the weight of the entire storage housing, affecting the overall stability of the 3D printer. An opening is provided near the fixed section in the storage section. The opening is used to output liquid to the position of the flow control component. The edge of the opening adopts an arc transition structure to reduce eddy current loss during liquid flow. The ratio of the area of ​​the opening to the bottom area of ​​the storage part is in the range of 0.3 to 0.5. The setting of the ratio of the area of ​​the opening to the bottom area of ​​the storage part is used to control the flow rate of liquid from the storage part to the fixed part. When the ratio of the area of ​​the opening to the bottom area of ​​the storage part is less than 0.3, the area of ​​the opening is too small, which will lead to an increase in liquid flow resistance and thus reduce the supply speed of liquid to the flow control component. When the ratio of the area of ​​the opening to the bottom area of ​​the storage part is greater than 0.5, the area of ​​the opening is too large, which will cause a large amount of liquid to rush into the fixed part instantly, thus exceeding the delivery capacity of the flow control component.

[0040] The dimensional relationship between the inner diameter of the output tube and the tip circle diameter of the driving gear satisfies the output matching equation, which is: The output matching equation is used to calculate the optimal inner diameter of the output tube based on the addendum circle diameter of the driving gear and the gear ratio. The input includes the addendum circle diameter of the driving gear. and gear ratio The output is the inner diameter of the output tube. The output pipe is made of stainless steel to withstand corrosion from high-temperature liquids. The wall thickness of the output pipe is 0.08 to 0.12 times its inner diameter. This wall thickness is designed to ensure sufficient strength when the output pipe is subjected to internal liquid pressure. If the wall thickness is less than 0.08 times its inner diameter, the insufficient wall thickness will cause deformation under liquid pressure, thus affecting the stability of liquid output. If the wall thickness is greater than 0.12 times its inner diameter, the excessive wall thickness will increase the weight of the output pipe, thereby increasing the load on the bottom of the storage housing.

[0041] The relationship between the center distance between the driving gear and the driven gear and the addendum circle diameters of the driving gear and the driven gear satisfies the center distance calculation equation, which is: The center distance calculation equation is used to calculate the theoretical center distance between two gears based on the addendum circle diameter of the driving gear, the addendum circle diameter of the driven gear, and the pressure angle of the gears. The input includes the addendum circle diameter of the driving gear. The tip circle diameter of the driven gear and the pressure angle of the gear The output is the center distance between the driving gear and the driven gear. The tooth surface of the driving gear is carburized and quenched to improve wear resistance, and the tooth surface of the driven gear is nitrided to improve surface hardness. The tooth surface roughness of the driving gear is smaller than that of the driven gear. The tooth surface roughness of the driving gear is in the range of 0.8μm to 1.2μm, and the tooth surface roughness of the driven gear is in the range of 1.5μm to 2.5μm.

[0042] The rotating rod and the driving gear are connected by an interference fit. The outer diameter of the end of the rotating rod is larger than the inner diameter of the center hole of the driving gear. The interference amount between the outer diameter of the end of the rotating rod and the inner diameter of the center hole of the driving gear is 0.001 to 0.003 times the outer diameter of the end of the rotating rod. This interference amount is used to ensure the connection between the rotating rod and the driving gear. When the interference amount is less than 0.001 times the outer diameter of the end of the rotating rod, insufficient interference will cause misalignment between the rotating rod and the driving gear. The fit between the fixed rod and the driven gear is loose, causing relative sliding during high-speed rotation. When the interference is greater than 0.003 times the outer diameter of the end of the rotating rod, the excessive interference will cause the center hole of the driving gear to crack during assembly, thus affecting the service life of the gear. The fixed rod and the driven gear are connected by a pin. The end of the fixed rod is provided with a radial through hole, and the inner wall of the center hole of the driven gear is provided with a pin hole corresponding to the radial through hole. The pin passes through the radial through hole and the pin hole to achieve a fixed connection between the fixed rod and the driven gear.

[0043] The outer wall of the storage housing is provided with a heating layer, which is used to maintain a stable temperature of the liquid inside the storage chamber. The heating layer consists of resistance heating wires wound around the outer surfaces of the storage section and the fixing section, and the power density of the heating layer is 0.5. ~1.5 Within a certain range, the power density of the heating layer is set to ensure that the liquid temperature in the storage cavity is maintained above the melting point of the material. When the power density of the heating layer is less than 0.5... When the heating layer provides insufficient heat, the liquid temperature drops, leading to solidification. This occurs when the power density of the heating layer exceeds 1.5. If the heating layer provides too much heat, the liquid temperature will be too high, resulting in material performance degradation. An insulation layer is provided between the outer wall of the storage shell and the heating layer. The insulation layer is made of ceramic fiber material to reduce heat loss to the external environment. The thickness of the insulation layer is in the range of 5mm to 10mm.

[0044] The ratio between the number of teeth on the driving gear and the number of teeth on the driven gear affects the conveying rate of the flow control component. The number of teeth on the driving gear ranges from 12 to 18, and the number of teeth on the driven gear ranges from 24 to 36. The number of teeth of the driven gear The ratio is in the range of 1:2 to 1:3. This ratio of the number of teeth on the driving gear to the number of teeth on the driven gear is set to achieve precise control of the liquid delivery rate. When the ratio of the number of teeth on the driving gear to the number of teeth on the driven gear is less than 1:2, the rotational speed of the driven gear... Excessive speed can cause the liquid delivery rate to exceed the discharge capacity of the outlet pipe, resulting in liquid backflow. When the ratio of the number of teeth of the driving gear to the number of teeth of the driven gear is greater than 1:3, the rotational speed of the driven gear... Too slow a flow rate will result in insufficient liquid delivery, thus failing to meet the material supply requirements during the 3D printing process.

[0045] The relationship between the depth of the receiving groove and the tooth heights of the driving gear and the driven gear satisfies the receiving groove depth optimization equation, which is: The optimization equation for the depth of the receiving groove is used to calculate the optimal depth of the receiving groove based on the tooth height of the driving gear, the tooth height of the driven gear, the center distance between the driving and driven gears, the sum of the addendum circle diameters of the driving and driven gears, and the inner diameter of the output pipe. The input includes the tooth height of the driving gear. tooth height of the driven gear The center distance between the driving gear and the driven gear The tip circle diameter of the driving gear Diameter of the tooth tip circle of the driven gear The sum of the inner diameter of the output tube and the inner diameter of the output tube. The output is the depth of the receiving slot. The optimization equation for the depth of the receiving groove is obtained by fitting through experiments. The coefficient 0.5 in the optimization equation for the depth of the receiving groove is the tooth height influence coefficient, and the coefficient 0.15 in the optimization equation for the depth of the receiving groove is the output pipe inner diameter correction coefficient.

[0046] The relationship between the pitch of the helical blades of the conveying screw, the outer diameter of the helical blades of the conveying screw, and the inner diameter of the top opening of the storage housing satisfies a pitch optimization equation, which is: The pitch optimization equation is used to calculate the pitch of the helical blades of the conveying screw based on the outer diameter of the helical blades of the conveying screw, the inner diameter of the top opening of the storage housing, and the center distance between the driving gear and the driven gear. The input includes the outer diameter of the helical blades of the conveying screw. Inner diameter of the top opening of the storage housing and the center distance between the driving gear and the driven gear The output is the pitch of the spiral blades of the conveying screw. The pitch optimization equation was obtained by fitting through experiments. The coefficient 1.2 in the pitch optimization equation is the outer diameter reference coefficient of the helical blade, and the coefficient 0.08 in the pitch optimization equation is the center distance influence coefficient.

[0047] The tooth height of the driving gear The tip circle diameter of the driving gear The tooth height of the driven gear is half the difference between the root circle diameter of the driving gear and the tooth height of the driven gear. The tooth tip circle diameter of the driven gear The difference between the root circle diameter of the driven gear and the storage housing is half; the height of the storage housing is the sum of the height of the storage section and the height of the fixed section; the volume of the storage section is the internal cavity volume of the storage section; the volume of the fixed section is the internal cavity volume of the fixed section; the bottom surface area of ​​the storage section is the cross-sectional area at the connection between the storage section and the fixed section; the gear transmission ratio is... The number of teeth of the driven gear The number of teeth of the driving gear The ratio of the pressure angle of the gear The angle between the normal to any point on the gear tooth profile curve and the circumferential tangent at that point; the interference fit is the diameter difference between the outer diameter of the end of the rotating rod and the inner diameter of the center hole of the driving gear; and the pitch of the helical blades of the conveying screw. The distance that the helical blades of the conveying screw travel axially in one revolution is the outer diameter of the helical blades of the conveying screw. The outermost diameter of the spiral blades of the conveying screw, and the inner diameter of the top opening of the storage housing. The diameter of the internal channel at the connection between the top of the storage housing and the conveying screw, and the depth of the receiving groove. The vertical distance by which the receiving groove extends radially inward from the side wall surface of the fixed part.

[0048] The second part of this invention provides a design method for a master-slave gear-type unidirectional conveying granular material 3D printing gear assembly, specifically including the following steps:

[0049] S01. Construct a master-slave gear type unidirectional conveying control framework, determine the meshing transmission relationship between the driving gear and the driven gear, set the number of teeth of the driving gear to be in the range of 12 to 18 teeth and the number of teeth of the driven gear to be in the range of 24 to 36 teeth, and set the ratio of the root circle diameter of the driving gear to the root circle diameter of the driven gear to be in the range of 1:1.5 to 1:2.5.

[0050] S02. Establish a game-theoretic optimization model for gear transmission parameters. The upper-level model, which aims to maximize liquid transport efficiency, inputs the number of teeth of the driving gear, the number of teeth of the driven gear, and the rotational speed of the driving gear. The lower-level model, which aims to maximize gear meshing stability, inputs the tip circle diameter of the driving gear and the tip circle diameter of the driven gear. The two models are coupled through the gear transmission ratio.

[0051] S03. Collect experimental data to determine the output matching equation coefficients. Set the test value of the active gear tip circle diameter in 2mm intervals within the range of 10mm~30mm. Set the test value of the gear transmission ratio in 0.2 intervals within the range of 2~3. Measure the corresponding optimal output tube inner diameter and fit it to obtain the output tube inner diameter reference coefficient of 0.3 in the output matching equation.

[0052] S04. Collect experimental data to determine the coefficients of the optimization equation for the depth of the receiving groove. Set test combinations for the tooth height of the driving gear and the tooth height of the driven gear within the range of 2mm~5mm and 3mm~8mm. Measure the optimal receiving groove depth under different ratios of the center distance between the driving gear and the driven gear and the sum of the top circle diameters of the driving gear and the driven gear. Fit the tooth height influence coefficient of 0.5 and the output pipe inner diameter correction coefficient of 0.15 in the optimization equation for the depth of the receiving groove.

[0053] S05. Collect experimental data to determine the coefficients of the pitch optimization equation. Set test combinations of the outer diameter of the conveying screw spiral blade and the inner diameter of the top opening of the storage shell within the range of 8mm~20mm and 10mm~25mm. Measure the optimal screw pitch of the conveying screw spiral blade under different parameter combinations. Fit the spiral blade outer diameter reference coefficient of 1.2 and the center distance influence coefficient of 0.08 in the pitch optimization equation.

[0054] S06. Adjust the gear transmission parameters according to the calculation results of the gear transmission parameter game optimization model. When the deviation between the liquid conveying efficiency index calculated by the upper model and the preset conveying efficiency threshold is greater than 8%, increase the rotation speed of the driving gear by 5% to 15%. When the gear meshing stability index calculated by the lower model is lower than 0.85, decrease the center distance between the driving gear and the driven gear by 3% to 10%.

[0055] Among them, the master-slave gear type unidirectional conveying control frame is a conveying control structure that drives the liquid to flow in a fixed direction through the meshing and rotation of the driving gear and the driven gear. The driving gear is connected to the drive motor through the rotating rod and receives the driving torque. The driven gear is supported by the fixed rod and rotates with the driving gear. The teeth of the two gears generate a pushing force on the liquid during the meshing process, thereby realizing the unidirectional conveying of the liquid.

[0056] The number of teeth on the driving gear is the number of teeth distributed on the circumference of the driving gear. In step S01, the number of teeth on the driving gear is set to a range of 12 to 18 teeth, and this number serves as an input parameter for the upper-level model in step S02. The number of teeth on the driven gear is the number of teeth distributed on the circumference of the driven gear. In step S01, the number of teeth on the driven gear is set to a range of 24 to 36 teeth, and this number serves as an input parameter for the upper-level model in step S02. The root circle diameter of the driving gear is the diameter of the circle containing the roots of the driving gear teeth, and the root circle diameter of the driven gear is the diameter of the circle containing the roots of the driven gear teeth. The ratio of the root circle diameter of the driving gear to the root circle diameter of the driven gear is set to a range of 1:1.5 to 1:2.5 in step S01.

[0057] The gear transmission parameter game optimization model consists of an upper-level model and a lower-level model. The upper-level model aims to maximize the liquid transport efficiency, and its objective function is expressed as follows: The objective function of the upper-level model is used to calculate the liquid transport efficiency index based on the number of teeth of the driving gear, the number of teeth of the driven gear, the rotational speed of the driving gear, and the tip circle diameters of the driving and driven gears. The inputs include the number of teeth of the driving gear. The unit is teeth, number of teeth of the driven gear The unit is the speed of the driving gear (tooth). The units are revolutions per minute and the tip circle diameter of the driving gear. The unit is mm and the diameter of the driven gear's tip circle. The unit is mm, and the output is a liquid transport efficiency index. The upper-level model is constrained by the ratio of the number of teeth on the driving gear to the number of teeth on the driven gear being in the range of 1:2 to 1:3, and the rotational speed of the driving gear being in the range of 100 rpm to 500 rpm. The lower-level model aims to maximize gear meshing stability, and its objective function is expressed as follows: The objective function of the lower-level model is used to calculate the gear meshing stability index based on the tip circle diameter of the driving gear, the tip circle diameter of the driven gear, the gear pressure angle, and the gear transmission ratio. The inputs include the tip circle diameter of the driving gear. The unit is mm, and it refers to the tip circle diameter of the driven gear. Units are mm, gear pressure angle The units are radians and the number of teeth on the driving gear. The unit is the number of teeth of the driven gear and the number of teeth of the driven gear. The unit is teeth, and the output is a gear meshing stability index. The constraints of the lower-level model are that the sum of the tip circle diameters of the driving gear and the driven gear is within the range of 30mm to 80mm, and the gear pressure angle is within the range of 0.35 radians to 0.44 radians. The two models are connected by a gear transmission ratio. Coupling, where the coupling term appears simultaneously in the objective function of the upper-level model and the objective function of the lower-level model and affects the optimization direction of both objectives.

[0058] The rotational speed of the driving gear is the angular velocity of its rotation around its geometric center axis. This rotational speed is used as an input parameter for the upper-level model in step S02. The driving gear's rotational speed is transmitted to the driving gear via a drive motor, transmission belt, and rotating rod. The tip circle diameter of the driving gear is the diameter of the circle containing the tips of its teeth. This tip circle diameter is used as an input parameter for the lower-level model in step S02. In step S03, the tip circle diameter of the driving gear is set to a range of 10mm to 30mm. The tip circle diameter of the driven gear is the diameter of the circle containing the tips of its teeth. This tip circle diameter is used as an input parameter for the lower-level model in step S02. The gear ratio is the ratio of the number of teeth on the driven gear to the number of teeth on the driving gear. In step S03, the gear ratio is set to a range of 2 to 3.

[0059] The output matching equation is a mathematical relationship between the tip circle diameter of the driving gear and the gear transmission ratio, used to calculate the inner diameter of the output tube. The output matching equation is expressed as follows: The output matching equation is used to calculate the inner diameter of the output tube based on the tip circle diameter of the driving gear and the gear transmission ratio. The input includes the tip circle diameter of the driving gear. The unit is mm and the gear ratio. The output is the inner diameter of the output tube. The unit is mm. The output tube inner diameter reference coefficient is the coefficient 0.3 in the output matching equation, which is obtained through experimental fitting in step S03. The test value of the drive gear tip circle diameter is the specific value of the drive gear tip circle diameter set in the experiment, which is set in step S03 at 2 mm intervals within the range of 10 mm to 30 mm. The test value of the gear transmission ratio is the specific value of the gear transmission ratio set in the experiment, which is set in step S03 at 0.2 intervals within the range of 2 to 3. The optimal output tube inner diameter is the best value of the output tube inner diameter obtained through experimental measurement under the given drive gear tip circle diameter test value and gear transmission ratio test value, which is used in step S03 to fit and obtain the output tube inner diameter reference coefficient.

[0060] The optimization equation for the depth of the receiving groove is a mathematical relationship used to calculate the depth of the receiving groove based on the tooth height of the driving gear, the tooth height of the driven gear, the center distance between the driving and driven gears, the tip circle diameter of the driving gear, the tip circle diameter of the driven gear, and the inner diameter of the output pipe. The optimization equation for the depth of the receiving groove is expressed as follows: The optimization equation for the depth of the receiving groove is used to calculate the depth of the receiving groove based on the tooth height of the driving gear, the tooth height of the driven gear, the center distance between the driving gear and the driven gear, the tip circle diameter of the driving gear, the tip circle diameter of the driven gear, and the inner diameter of the output pipe. The inputs include the tooth height of the driving gear. Units are mm, driven gear tooth height The unit is mm, and it refers to the center distance between the driving gear and the driven gear. The unit is mm, and it refers to the tip circle diameter of the driving gear. The unit is mm, and it refers to the tip circle diameter of the driven gear. The units are mm and the inner diameter of the output tube. The unit is mm, and the output is the depth of the receiving groove. The unit is mm. The tooth height influence coefficient is 0.5, which is the coefficient in the optimization equation for the receiving groove depth. This tooth height influence coefficient is obtained through experimental fitting in step S04. The output pipe inner diameter correction coefficient is 0.15, which is the coefficient in the optimization equation for the receiving groove depth. This output pipe inner diameter correction coefficient is obtained through experimental fitting in step S04. The tooth height of the driving gear is half the difference between the diameter of the driving gear tip circle and the diameter of the driving gear root circle. In step S04, the tooth height of the driving gear is set to be in the range of 2mm to 5mm. The tooth height of the driven gear is half the difference between the diameter of the driven gear tip circle and the diameter of the driven gear root circle. In step S04, the tooth height of the driven gear is set to be in the range of 3mm to 8mm. The test combination of driving gear tooth height and driven gear tooth height is the matching value of driving gear tooth height and driven gear tooth height set in the experiment. This test combination of driving gear tooth height and driven gear tooth height is used in step S04 to measure the optimal receiving groove depth. The center distance between the driving gear and the driven gear is the straight-line distance between the geometric centers of the driving gear and the driven gear. In step S04, this center distance is calculated as the ratio of the sum of the tip circle diameters of the driving gear and the driven gear. In step S06, the center distance between the driving gear and the driven gear is adjusted by reducing it by 3% to 10%. The sum of the tip circle diameters of the driving gear and the driven gear is the sum of their respective tip circle diameters. In step S04, this sum is used to calculate the ratio of the center distance between the driving gear and the driven gear. The optimal receiving groove depth is the best value obtained experimentally under a given combination of driving gear tooth height and driven gear tooth height test conditions. In step S04, this optimal receiving groove depth is used to fit the tooth height influence coefficient and the output pipe inner diameter correction coefficient. The depth of the receiving groove is the vertical distance that the receiving groove extends radially inward from the side wall surface of the fixing part. The depth of the receiving groove is calculated by the receiving groove depth optimization equation.

[0061] The pitch optimization equation is a mathematical relationship for calculating the pitch of the conveying screw's helical blades based on the outer diameter of the conveying screw's helical blades, the inner diameter of the top opening of the storage housing, and the center distance between the driving gear and the driven gear. The pitch optimization equation is expressed as follows: The pitch optimization equation is used to calculate the pitch of the conveying screw's helical blades based on the outer diameter of the conveying screw's helical blades, the inner diameter of the top opening of the storage housing, and the center distance between the driving gear and the driven gear. The inputs include the outer diameter of the conveying screw's helical blades. Unit: mm; inner diameter of the top opening of the storage housing The unit is mm and refers to the center distance between the driving gear and the driven gear. The unit is mm, and the output is the pitch of the screw blades of the conveyor. The unit is mm. The outer diameter reference coefficient of the helical blade is coefficient 1.2 in the pitch optimization equation, which is obtained through experimental fitting in step S05. The center distance influence coefficient is coefficient 0.08 in the pitch optimization equation, which is also obtained through experimental fitting in step S05. The outer diameter of the conveying screw helical blade is the diameter of the outermost edge of the helical blade of the conveying screw, which is set to a range of 8mm to 20mm in step S05. The inner diameter of the top opening of the storage housing is the diameter of the internal channel at the connection between the top of the storage housing and the conveying screw, which is set to a range of 10mm to 25mm in step S05. The test combination of the outer diameter of the conveying screw helical blade and the inner diameter of the top opening of the storage housing is the matching value of the outer diameter of the conveying screw helical blade and the inner diameter of the top opening of the storage housing set in the experiment. This test combination is used in step S05 to measure the optimal pitch of the conveying screw helical blade. The optimal pitch of the conveying screw helical blade is the best value obtained through experimental measurement under the test combination of a given outer diameter of the conveying screw helical blade and the inner diameter of the top opening of the storage housing. This optimal pitch is used in step S05 to fit and obtain the outer diameter reference coefficient and center distance influence coefficient of the helical blade. The pitch of the conveying screw helical blade is the axial distance traveled by the helical blade during one revolution of the conveying screw, and is calculated using a pitch optimization equation.

[0062] The liquid delivery efficiency index is the ratio of the volumetric flow rate of liquid delivered to the output pipe by the flow control component per unit time to the power consumed by the drive motor. This index is calculated by the upper-level model in step S02 and compared with a preset delivery efficiency threshold in step S06. The gear meshing stability index is the fluctuation coefficient of the contact area between the teeth of the driving and driven gears during rotation. This index is calculated by the lower-level model in step S02 and compared with a value of 0.85 in step S06. The preset delivery efficiency threshold is the minimum required value for the liquid delivery efficiency index determined based on the material supply requirements during 3D printing. This threshold is used in step S06 to calculate the deviation from the liquid delivery efficiency index. The gear pressure angle is the angle between the normal to any point on the gear tooth profile curve and the circumferential tangent at that point. This angle serves as an input parameter for the lower-level model in step S02. The inner diameter of the output tube is the diameter of the internal channel of the output tube. The inner diameter of the output tube is calculated by the output matching equation in step S03. The inner diameter of the output tube is used as the input parameter of the cavity depth optimization equation in step S04.

[0063] Specifically, the principle of this invention is as follows: The fundamental reason why this invention can solve the problem of insufficient accuracy in liquid flow control lies in replacing the traditional single-stage drive structure with a two-stage master-slave gear transmission mechanism. The driving gear and driven gear form an adjustable transmission ratio through the difference in their tooth count ratios. When the driving gear rotates, the driven gear rotates synchronously at different speeds. The teeth of both gears contact the liquid within the receiving groove, and the directional delivery of the liquid is achieved through the tooth surface pushing action. The gear transmission ratio calculation equation establishes a mathematical relationship between the number of teeth, rotational speed, and diameter, allowing precise control of the driven gear's rotational speed by adjusting the driving gear's speed, thereby regulating the liquid delivery rate. The output matching equation correlates the output pipe's inner diameter with the gear parameters, ensuring that the output channel size matches the gear's delivery capacity and preventing liquid accumulation or backflow. The receiving groove depth optimization equation comprehensively considers the influence of tooth height, center distance, and the output pipe's inner diameter to determine the gear embedding depth, ensuring that the gear's force on the liquid reaches its optimal state. The screw pitch optimization equation coordinates the parameter matching between the conveying screw and the flow control components, achieving full-process optimization from particle delivery to liquid control, conforming to the basic principles of fluid mechanics and mechanical transmission.

[0064] The following is a specific embodiment 1 of the present invention: A technical team is conducting design and optimization work on a master-slave gear-type unidirectional conveying gear assembly for a 3D printing system of granular thermoplastic materials. The team's technical task is to configure a high-precision liquid delivery control system for an industrial-grade 3D printing equipment, requiring a stable material supply rate during the printing process and avoiding the backflow and blockage problems existing in traditional screw conveying methods. Figure 3As shown, the technical team used the master-slave gear-type unidirectional conveying control scheme provided by this invention for system design.

[0065] The technical team first constructed a master-slave gear-type unidirectional conveying control framework according to step S01, determining that the number of teeth on the driving gear was 15 and the number of teeth on the driven gear was 30, satisfying the requirement that the tooth ratio be within the range of 1:2 to 1:3. The root circle diameter of the driving gear was set to 12mm, and the root circle diameter of the driven gear was set to 24mm, with a ratio of 1:2, which meets the design constraint of 1:1.5 to 1:2.5. Both the driving and driven gears adopted an involute tooth profile design, the gear pressure angle was selected as 0.38 radians, and the initial diameter of the tip circle of the driving gear was determined to be 18mm.

[0066] In step S02, the technical team established a game-theoretic optimization model for gear transmission parameters. The upper-level model aims to maximize liquid delivery efficiency, with input parameters including 15 teeth on the driving gear, 30 teeth on the driven gear, and a rotational speed of 300 rpm for the driving gear. The lower-level model aims to maximize gear meshing stability, with input parameters including an 18mm tip circle diameter for the driving gear, a 36mm tip circle diameter for the driven gear, and a gear pressure angle of 0.38 radians. The two models are coupled through a gear ratio of 2. The liquid delivery efficiency index calculated by the upper-level model is 4.85, and the gear meshing stability index calculated by the lower-level model is 0.91, both meeting the design requirements.

[0067] The output matching equation coefficients were determined based on the experimental data collected in step S03. The technical team experimentally measured the optimal output tube inner diameter under test values ​​for the active gear tip circle diameters of 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, and 30mm, and gear transmission ratios of 2.0, 2.2, 2.4, 2.6, 2.8, and 3.0. The experimental data are shown in Table 1.

[0068] Table 1. Test data on the optimal output tube inner diameter corresponding to the tip circle diameter of the driving gear and the gear ratio.

[0069]

[0070] The technical team obtained a baseline coefficient of 0.3 for the inner diameter of the output tube by performing nonlinear fitting on the experimental data in Table 1. Based on the output matching equation, the inner diameter of the output tube was calculated to be 7.64 mm. The team selected a stainless steel tube with an inner diameter of 8 mm as the output tube, setting the wall thickness to 0.8 mm. The ratio of wall thickness to inner diameter was 0.1, which meets the design requirement of 0.08 to 0.12 times.

[0071] In step S04, the technical team collected experimental data to determine the coefficients of the optimization equation for the receiving groove depth. The tooth height of the driving gear is 3mm, the tooth height of the driven gear is 6mm, and the center distance between the driving and driven gears is calculated to be 27.5mm. The technical team measured the optimal receiving groove depth under different driving gear tooth heights, driven gear tooth heights, and the ratio of the center distance to the sum of the tooth tip circle diameters. Through experimental fitting, the tooth height influence coefficient was found to be 0.5, and the output pipe inner diameter correction coefficient was 0.15. According to the receiving groove depth optimization equation, the receiving groove depth was calculated to be 3.43mm. The team opened a receiving groove with a depth of 3.5mm on the side wall of the fixed part. The ratio of the receiving groove depth to the driving gear tooth height is 1.17, which meets the design range of 0.4 to 0.6 times the tooth height.

[0072] The coefficients of the pitch optimization equation were determined based on the experimental data collected in step S05. The outer diameter of the helical blades of the conveying screw was set to 14 mm, and the inner diameter of the top opening of the storage shell was set to 16 mm, with a ratio of 0.875, which meets the requirement of 0.85~0.95. The technical team conducted experimental measurements within the range of 8 mm~20 mm for the outer diameter of the helical blades of the conveying screw and 10 mm~25 mm for the inner diameter of the top opening of the storage shell, obtaining a reference coefficient of 1.2 for the outer diameter of the helical blades and a center distance influence coefficient of 0.08. Based on the pitch optimization equation, the pitch of the helical blades of the conveying screw was calculated to be 19.07 mm, and the team set the pitch of the helical blades of the conveying screw to 19 mm.

[0073] In step S06, the technical team adjusts the gear transmission parameters based on the calculation results of the game-theoretic optimization model. The liquid delivery efficiency index calculated by the upper-level model is 4.85, and the preset delivery efficiency threshold is set to 4.5. The deviation between the two is 7.78%, which is less than the adjustment threshold of 8%. Therefore, the rotational speed of the drive gear remains unchanged at 300 revolutions per minute. The gear meshing stability index calculated by the lower-level model is 0.91, which is higher than the required value of 0.85. The center distance between the gears does not need to be adjusted.

[0074] The technical team completed a master-slave gear-type unidirectional conveying gear assembly, which includes a storage housing, a conveying screw, a driving gear, a driven gear, a rotating rod, and an output pipe. The storage housing consists of a storage section and a fixing section. The storage section is cylindrical with an outer diameter of 45mm and a height of 80mm. The fixing section is frustoconical with a cone angle of 20°, an upper end diameter of 45mm, a lower end diameter of 30mm, and a height of 35mm. The storage section has a volume of 127.23 cubic meters. The volume of the fixed part is 31.41. The volume ratio of the two is 4.05:1, which meets the requirement of a range of 3:1 to 5:1. The storage section, located near the fixed section, has an area of ​​636.17 square meters. The opening has a bottom surface area of ​​1590.43 square meters. The ratio of the opening area to the bottom area is 0.4, which meets the design requirements of 0.3 to 0.5.

[0075] The rotating rod is made of stainless steel with an outer cylindrical diameter of 6mm and a length of 85mm. The ratio of the rotating rod length to the height of the storage housing is 0.74, meeting the requirements of 0.6~0.9. The end of the rotating rod has a keyway structure with a depth of 0.72mm, and the ratio of the keyway depth to the outer diameter of the rotating rod is 0.12, meeting the design range of 0.1~0.15. The rotating rod and the driving gear are connected by an interference fit. The outer diameter of the rotating rod end is 6.012mm, the inner diameter of the driving gear's center hole is 6mm, and the interference is 0.012mm. The ratio of the interference to the outer diameter of the rotating rod end is 0.002, meeting the requirements of 0.001~0.003. The fixed rod is made of alloy steel with an outer cylindrical diameter of 4mm. The fixed rod and the driven gear are connected by a pin. The outer wall of the storage housing is equipped with a power density of 1.0... The heating layer is formed by winding resistance heating wire, and an 8mm thick ceramic fiber insulation layer is provided between the outer wall of the storage shell and the heating layer.

[0076] The technological advancements of this invention compared to traditional screw conveyors primarily lie in achieving unidirectional forced liquid delivery through master-slave gear meshing, eliminating the liquid backflow problem inherent in traditional screw conveyors. During rotation, the driving and driven gears generate a continuous pushing force on the liquid, and the gear teeth form a closed liquid delivery channel at the meshing position, preventing reverse flow when pressure fluctuates. By precisely controlling the liquid delivery rate through adjusting the gear ratio and the rotational speed of the driving gear, the unstable printing quality caused by fluctuations in the liquid supply rate in traditional methods is avoided. The gear transmission parameter game-theoretic optimization model optimizes both liquid delivery efficiency and gear meshing stability as dual objectives, resolving the contradiction between delivery efficiency and transmission reliability that cannot be simultaneously achieved under a single optimization objective. The optimized equation for the receiving tank depth comprehensively considers the coupling relationship between gear tooth height, center distance, and the inner diameter of the output pipe, ensuring sufficient contact between the gear and the liquid inside the receiving tank while avoiding interference between the gear and the bottom of the receiving tank, thus improving the long-term operational stability of the system.

[0077] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A master-slave gear type unidirectional conveying granular material 3D printing gear assembly, characterized in that... The system includes a storage shell and a conveying assembly. The top of the storage shell is connected to the bottom of the conveying assembly. The conveying assembly is used to convey the liquid formed by melting particulate material into the storage shell. A flow control assembly is located in the middle of the storage shell. The flow control assembly includes a driving gear and a driven gear. The driving gear and the driven gear are meshed together. The center of the driving gear is fixedly connected to a drive assembly. The drive assembly is used to drive the driving gear to rotate. The rotation of the driving gear drives the driven gear to rotate synchronously. The liquid is pushed to the bottom of the flow control assembly through the gear surface. An output pipe is located at the center of the bottom of the storage shell. The output pipe is used to discharge the liquid conveyed by the rotation of the flow control assembly. The transmission relationship between the driving gear and the driven gear is determined by the gear transmission ratio calculation equation, which determines the rotational speed and the tip circle diameter of the driven gear.

2. The gear assembly according to claim 1, characterized in that, The driving gear and the driven gear are dual-type gear structures with the same tooth profile but different numbers of teeth. The outer diameter of the driving gear teeth is smaller than that of the driven gear teeth, and the number of teeth of the driving gear is smaller than that of the driven gear.

3. The gear assembly according to claim 2, characterized in that, Both the driving gear and the driven gear adopt an involute tooth profile design. The ratio of the root circle diameter of the driving gear to the root circle diameter of the driven gear is 1:1.5 to 1:2.

5.

4. The gear assembly according to claim 3, characterized in that, The drive assembly includes a rotating rod and a fixed rod. The rotating rod is fixedly connected to the geometric center of the drive gear and is used to drive the drive gear to rotate around its geometric center axis. The fixed rod is fixed at the geometric center of the driven gear.

5. The gear assembly according to claim 4, characterized in that, The central axis of the rotating rod is perpendicular to the plane where the driving gear is located, and the central axis of the fixed rod is perpendicular to the plane where the driven gear is located. The outer cylindrical diameter of the rotating rod is larger than the outer cylindrical diameter of the fixed rod.

6. The gear assembly according to claim 5, characterized in that, The rotating rod is made of stainless steel, and the fixed rod is made of alloy steel. The ratio of the length of the rotating rod to the height of the storage shell is 0.6 to 0.

9.

7. The gear assembly according to claim 6, characterized in that, One end of the rotating rod is connected to the power system of the 3D printer. The power system includes a drive motor and a transmission belt. The end of the rotating rod is provided with a keyway structure, and the inner side of the transmission belt is provided with a key tooth structure that mates with the keyway structure.

8. A design method for a master-slave gear-type unidirectional conveying granular material 3D printing gear assembly, characterized in that, Includes the following steps: A master-slave gear-type unidirectional conveying control framework is constructed, and the meshing transmission relationship between the driving gear and the driven gear is determined. The number of teeth on the driving gear is set to 12 to 18 teeth and the number of teeth on the driven gear is set to 24 to 36 teeth. The ratio of the root circle diameter of the driving gear to the root circle diameter of the driven gear is set to 1:1.5 to 1:2.

5. A game-theoretic optimization model of gear transmission parameters is established. The upper-level model with the goal of maximizing liquid conveying efficiency is input with the number of teeth on the driving gear, the number of teeth on the driven gear, and the rotational speed of the driving gear. The lower-level model with the goal of maximizing gear meshing stability is input with the tip circle diameter of the driving gear and the tip circle diameter of the driven gear. The two models are coupled through the gear transmission ratio. Collect experimental data to determine the coefficients of the output matching equation, the coefficients of the cavity depth optimization equation, and the coefficients of the pitch optimization equation; adjust the gear transmission parameters based on the calculation results of the game optimization model for gear transmission parameters.

9. The design method according to claim 8, characterized in that, The objective function of the upper-level model is used to calculate the liquid transport efficiency index based on the number of teeth of the driving gear, the number of teeth of the driven gear, the rotational speed of the driving gear, and the tip circle diameters of the driving gear and the driven gear. The objective function of the lower-level model is used to calculate the gear meshing stability index based on the tip circle diameters of the driving gear and the driven gear, the gear pressure angle, and the gear transmission ratio.

10. The design method according to claim 9, characterized in that, When the deviation between the liquid transport efficiency index calculated by the upper-level model and the preset transport efficiency threshold is greater than 8%, the rotation speed of the drive gear is increased by 5% to 15%. When the gear meshing stability index calculated by the lower-level model is lower than 0.85, the center distance between the drive gear and the driven gear is reduced by 3% to 10%.

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