Rotary table for manufacturing angular components by direct energy deposition processes.

Description

1 / 7 Rotary table for manufacturing angular components by direct energy deposition processes. Field of Invention

[001] The present invention relates to an adaptable rotary table that allows the addition of one more degree of freedom in the Cartesian manufacturing structure, thereby expanding the range of possibilities and geometries for parts manufactured using this process. This falls within the field of mechanical engineering, in particular in the additive manufacturing process of metals that uses directed energy deposition (DED), in which the mechanism of robotic welding is used to deposit layers that, when superimposed, form a component or part. Background of the Invention

[002] The conventional manufacturing of metal equipment can involve numerous forming processes, such as forging, casting, rolling, machining, among others. Considering that the combination of these processes can slow down production and increase the costs inherent to the chosen method, Metal Additive Manufacturing (MAM) emerges as an alternative to such methods, being one of the pillars of Industry 4.0.

[003] Among the additive manufacturing methods for metallic components, we can mention powder bed fusion (PBF), binder jetting (BJ), sheet rolling (SL), and energy directed deposition (EDD). Each process has advantages and disadvantages, differing primarily in the deposition rate and thickness of the deposited layer. However, processes based on EDD are superior in the aspects mentioned above, in addition to having a low equipment cost compared to other MAM methods, a wide variety of materials, and meeting the hardness and mechanical stress requirements in industrial applications.

[004] Despite the increasing use of DED subprocesses, all have limitations regarding the geometry of the parts produced and the degrees of Petition 870250012736, dated 02 / 17 / 2025, page 12 / 22 2 / 7 freedom required. In a Cartesian structure with three axes (X, Y, and Z), there are limitations in the fabrication of complex geometries. These restrictions are related to the need for supports, which increase material consumption and require post-processing, as well as the orientation of the layers, which can cause point voids or overloads in certain areas.

[005] Geometries with inclinations cannot be manufactured using only linear axes. The process requires tilting the welding torch or the substrate to achieve the desired angle. In Cartesian machines, integrating a rotary table can be simpler than implementing a mechanism for tilting the torch.

[006] Numerous patents have already been filed on adaptation methods in the field of MAM, however little research has been done on adding another axis to the machines, and what aspects would be improved with such an invention.

[007] One can take as an example US patents 11951560B2 and 11945042B2, which present methods of additive manufacturing by arc deposition (MADA), a DED subprocess based on electric arc, in titanium alloys and magnesium alloys, respectively. The systems used by both have 3 degrees of freedom, which makes it impossible to create complex metal parts or components without the addition of supports, which reinforces the need for a system that has a rotating axis.

[008] Patent BR1020230104967 refers to a modification in a CNC milling machine for use in additive / subtractive manufacturing, which integrates coupling parts that vary between the welding torch and the milling machine. With a metal protection plate in the work area and a rubber cushion between this plate and the work table, the mechanism includes a vertical adjustment of the torch by horizontal linear guides, providing precision during the manufacturing process. In this sense, the rotary table can be integrated into the existing system, requiring only adjustments to the controller already in use, expanding the versatility and efficiency of the equipment.

[009] In addition, patent BR 112023016774-4 A2 describes a device and method for DED that consists of a welding system that creates an electric arc, responsible for generating a weld pool on a work surface. Petition 870250012736, dated 02 / 17 / 2025, page 13 / 22 3 / 7 In this device, a wire feeder is configured to feed wire towards the weld pool, thus generating a weld joint. Additionally, the device also comprises an enclosure that surrounds the workpiece and a protective gaseous atmosphere for the arc, for which a suction device removes gas from the work zone and subsequently reintroduces it into the process atmosphere.

[010] The inventions described in patents US10330182B2 and MU 91009734 U2 report systems that use pulleys to transfer energy between different components, with the former focusing more on a differential pulley transmission. This design option provides precise movements, where the driving pulley is larger than the driven pulley; in this sense, the system will have a high input speed and high output torque. The latter, however, reports a pulley system that must have greater durability and resistance, as it is used in demanding environments.

[011] The systems do not focus on applying this type of reduction at high temperatures, which is required in DED processes. In this sense, priority is given to a position where the belt / pulley assembly does not absorb heat from the welding torch in the table geometry.

[012] Another important aspect is the method used to control all Cartesian coordinates and compile them for the manufacture of the part. The control of the Cartesian structure is done by software that turns a conventional computer into a CNC (computer numerical control) controller. This interprets the commands in a G-CODE file, generated from a computer-aided design (CAD) model, and sends the instructions from this file so that the stepper motors can move in the requested direction.

[013] For example, patent EP 1 302 829 B1 relates to a numerical controller developed to handle a machining center that has a rotating axis. This is designed to handle the machined part more easily. For the control of this system, a machining program was developed that communicates the codes using a CAM (computer-aided manufacturing) system. Petition 870250012736, dated 02 / 17 / 2025, page 14 / 22 4 / 7

[014] It is worth highlighting the impact of the inclination of the construction of the parts on the quality of the layers deposited in DED processes, since some studies report that the orientation of the surface directly influences the adhesion and uniformity of the deposition. A rotary table, controllable and precise, can offer better conditions for the deposition of uniform layers in regions with difficult access for the extruder, reducing manufacturing defects such as porosity, humping and lack of fusion between layers. OBJECTIVES OF THE INVENTION

[015] The present invention aims to integrate what utility models have partially addressed in relation to the intended technical field, using MAM for the manufacture of tubular bends. Considering the significant advantages found with the sum of these methods, the innovation aims to further consolidate MAM as an effective and promising method.

[016] For MAM, the rotary table enables the creation of new geometries, such as the creation of angled curves for piping. The process has great potential and offers certain advantages over conventional manufacturing methods because, in addition to minimizing material loss compared to conventional machining, it allows for the customized manufacturing of custom-made parts, eliminating the need to create a new casting die, for example, for each variation in pipe diameter.

[017] The present invention relates to a rotary table for manufacturing angular components by direct energy deposition, comprising the following components: side supports (1); lower base (2); work table (3); upper supports (4); shaft (5); spherical bearings (6); motor support (7); reduction (8); motor (9).

[018] The rotary table can be used in conjunction with other inventions that make up the area of ​​additive manufacturing of metals, adapting to router type machines or CNC milling machines. Brief Description of the Drawings Petition 870250012736, dated 17 / 02 / 2025, page 15 / 22 5 / 7

[019] The attached drawings provide a detailed representation of the rotary table according to the present invention, highlighting the configuration of its components and the integrated operation of the system: Figure 1 illustrates a perspective view of the rotary table. Figure 2 shows a detailed view of the moving components of the rotary table for processes based on direct energy deposition. Detailed Description of the Invention

[020] As observed in Figure 1, the assembly describes the operation of the rotary table and how it works. The side supports (1) are structural components that provide lateral stability to the table and perform the function of supporting vertical and lateral loads, minimizing bending and vibration during use. In addition, each side support is connected to the lower base by means of screws that have the thread embedded in the base itself, ensuring integrity and alignment during operation.

[021] The lower base (2), as illustrated in Figure 2, acts to level and provide stability to the other components, also allowing the alignment of the two side supports and serving as a fixation point for them in the Cartesian robot, having at least 2 points for fixation.

[022] The work table (3), as illustrated in Figure 2, is the main contact surface, on which the layers will be deposited using the DED process. The layers will be manipulated to acquire the desired shape, which in this case will be the angular components. On it, there are T-profiles oriented horizontally in the opposite direction to the axis, for fixing the substrate, which ensures stability during the deposition process.

[023] The shaft (5), as illustrated in Figure 2, is a component that facilitates the precise movement of the worktable (3). It is coupled directly to the table and is responsible for transmitting the rotational movement of the stepper motor to the shaft, which will allow the table to move radially. Each end of the table has a shaft, one of which is connected to the motor through a system of synchronous pulleys. The transmission system is Petition 870250012736, dated 17 / 02 / 2025, page 16 / 22 6 / 7 designed to minimize friction and ensure process stability, which is crucial for the production of complex and high-quality geometries.

[024] The bearings (6), as illustrated in Figure 2, are used to reduce friction between the shaft and the rotary table structure, as well as to support radial and axial loads, which allows for gradual and smooth movement.

[025] The motor support (7), as illustrated in Figure 2, is a component that secures the motor to the table structure, keeping the motor stable during operation by ensuring that it is aligned with the reduction system.

[026] The reduction system (8), as illustrated in Figure 2, composed of the synchronous pulley system, is a mechanism designed to adjust the motor's rotational speed to a controlled speed, decreasing the rotational speed and increasing the final torque. The ratio between the diameters of the pulleys will determine the speed reduction, with a minimum ratio of 1:6 being used in order to provide the precision necessary for the satisfactory use of the rotary table.

[027] The motor (9), as illustrated in Figure 2, used converts electrical pulses into discrete angular motion, called a “step”, moving at 1.8 degrees per step. This limit is not sufficient for control with the desired accuracy. This demands a mechanical reduction that improves precision, since the machine movement must be as smooth as possible to obtain the desired geometries.

[028] The angle adjustment control of the table is computerized, which allows for better precision and operational applicability. Thus, CNC-based software is used, which is responsible for communication with the stepper motors, through drivers and a CNC controller board. Examples of embodiments of the invention

[029] There are Cartesian framework models that operate with all degrees of freedom in DED processes. However, for adaptations to existing machines, recent research has explored the addition of a fourth. Petition 870250012736, dated 02 / 17 / 2025, page 17 / 22 7 / 7 axis, using an adaptable rotary table. In addition to these studies, some machining centers incorporate rotary axes in a similar way to the structure analyzed, expanding manufacturing capabilities and allowing greater flexibility in the manufacturing process. Petition 870250012736, dated 17 / 02 / 2025, page 18 / 22

Claims

1 / 2 CLAIMS 1. Rotary table for additive manufacturing of metals by direct energy deposition, characterized by comprising a base structure and a computerized angular adjustment mechanism, which allows for greater operational applicability, enabling the manufacture of various types of angular geometries.

2. Rotary table for additive manufacturing of metals, according to claim 1, characterized by having a structure with few components, being connected to two lateral bearings through roller bearings, in addition to including clamping surfaces that guarantee angular precision during the direct energy deposition process.

3. Worktable for additive manufacturing of metals, according to claims 1 and 2, characterized by having a plate with T-profiles for fixing the substrate, being the main surface where the deposition of layers of metallic material occurs to form the angular components.

4. Lower base for rotary table, according to claims 1 and 2, characterized by acting in the leveling and stabilization of the machine components, allowing the alignment of the side bearings and serving as a fixation for a Cartesian robot, through two or more support points.

5. Reduction system, according to claim 1, characterized by being constituted of a set of synchronous pulleys, so as to adjust the rotational speed of the motor to a controlled rotation, decreasing the angular velocity and increasing the final torque.

6. The motor support, according to claim 1, characterized by having internal structural reinforcements and its fixation being made by screws on the sides of the bearing, which provides resistance to the weight exerted by the motor.

7. The motor support, according to claims 1 and 6, characterized by having a geometry that has two plates of the same size, and a larger one, where the motor is fixed by screwing at its 4 ends.

8. A bearing assembly, according to claims 1 and 2, characterized by being fixed with interference to the bearing housings, aiming to reduce friction between the shaft and the table structure, while supporting radial and axial loads, and allowing gradual movement of the table.

9. The shafts connecting the bearings to the worktable, according to claims 1 and 8, characterized by being fixed to the bearings through interference, and are responsible for transmitting the movement from the motor to the worktable. Petition 870250012736, dated 17 / 02 / 2025, pp. 20 / 22

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