Apparatus for removing excess material and method of operating the same

Abstract

An apparatus and method for removing excess material, preferably a powder, from a cavity of a component, wherein the apparatus includes: a platform for retaining the component, preferably an additively manufactured component, a drive mechanism being coupled to the platform, wherein the drive mechanism is configured to rotate the component being retained by the platform independently around two orthogonal spatial directions and each with an unlimited angular deflection, an actuator for mechanically actuating the platform during a removal of the excess material, and a housing, defining a working space in which the excess material can be removed from the cavity, wherein the housing seals the working space against an environment, and wherein any electrical components for the drive mechanism are arranged out of the working space.

Claims

1. An apparatus for removing excess material from a cavity of a component, comprising: a platform for retaining the component, a drive mechanism being coupled to the platform, wherein the drive mechanism is configured to rotate the component being retained by the platform independently around two orthogonal spatial directions (X, Y) and each with an unlimited angular deflection (α, β), an actuation means for mechanically actuating the platform during a removal of the excess material, and a housing, defining a working space in which the excess material is removable from the cavity, wherein the housing seals the working space against an environment, wherein any electrical components for the drive mechanism are arranged out of the working space, and wherein the drive mechanism is configured to rotate the platform independently around the two orthogonal spatial directions (X, Y) relative to the housing while the platform is inside the housing.

2. The apparatus according to claim 1, wherein the drive mechanism comprises two independently controllable worm gears, one worm gear being configured for rotation of the platform around one spatial direction (X, Y) each, and wherein any electrical motor for driving said worm gears and any electrical connections are arranged outside of the working space.

3. The apparatus according to claim 1, wherein the actuation means, is arranged inside the working space, and driven by a pressurised inert gas and without any electrical gear.

4. The apparatus according to claim 1, wherein the actuation means comprises a first vibration generator being configured for actuating the platform at a first frequency and a second vibration generator being configured for actuating the platform at a second frequency being different from the first frequency.

5. The apparatus according to claim 4, wherein the first vibration generator is a low frequency, high impact generator, and the second vibration generator is a high frequency, low impact generator.

6. The apparatus according to claim 4, wherein the first frequency comprises frequencies from 1 mHz to 1 Hz.

7. The apparatus according to claim 4, wherein the second frequency comprise frequencies from 1 Hz to 10 kHz.

8. The apparatus according to claim 4, wherein the first vibration generator and the second vibration generator are independently controllable.

9. The apparatus according to claim 1, wherein the apparatus is configured to allow for driving and actuating the platform while retaining large masses.

10. The apparatus according to claim 1, further comprising: a control unit being connected to the drive mechanism and the actuation means.

11. A method of operating the apparatus according to claim 1, wherein the apparatus is controlled by a computer program which drives and actuates the platform under consideration of gravity, cavity openings of the component and an ideal excess material removal path.

12. The apparatus according to claim 1, wherein the excess material comprises a powder.

13. The apparatus according to claim 1, wherein the component comprises an additively manufactured component.

14. The apparatus according to claim 9, wherein the large masses are more than 50 kg.

15. An apparatus for removing excess material from a cavity of a component, comprising: a housing that defines a working space in which the excess material is removable from the cavity, wherein the housing seals the working space against a surrounding environment; a platform disposed within the housing and configured to retain the component; and a drive mechanism configured to rotate the platform independently around two orthogonal spatial directions (X, Y) inside of and relative to the housing, wherein the drive mechanism comprises a motor disposed outside the housing; a drive train that connects the motor to the platform; and a seal that provides a seal between the housing and the drive train where the drive train passes through the housing.

16. The apparatus of claim 15, further comprising an actuation means for mechanically actuating the platform during removal of the excess material.

17. An apparatus for removing excess material from a cavity of a component, comprising: a housing that defines a working space in which the excess material is removable from the cavity and that is at least in fluid communication with an additive manufacturing space when an additive manufacturing process occurs, wherein the housing seals the working space against a surrounding environment; a platform disposed within the housing and configured to retain the component; and a drive mechanism configured to rotate the platform independently around two orthogonal spatial directions (X, Y), wherein the drive mechanism comprises a motor disposed outside the housing and a drive train that connects the motor to the platform, and wherein any electrical components for the drive mechanism are arranged out of the working space.

18. The apparatus of claim 17, wherein the housing defines both the working space and the additive manufacturing space, and wherein the housing seals both the working space and the additive manufacturing space from the surrounding environment.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 indicates in a schematic view an additive powder bed fusion process with a component shown during its additive manufacture.

(2) FIG. 2 shows a simplified schematic of an apparatus for the removal of excess material from an inside of an additively manufactured component according to the present invention.

DETAILED DESCRIPTION OF INVENTION

(3) Like elements, elements of the same kind and identically acting elements may be provided with the same reference numerals in the Figures.

(4) FIG. 1 shows an additive manufacturing device 200. The device 200 may constitute a state of the art hardware for selective laser melting or electron beam melting. The device 200 comprises a build platform or substrate plate 11. On the substrate plate 11, a component 10 is advantageously directly manufactured, i.e. welded. Preferably the component 10 is buildup in the device 200 out of a powder bed of a powder P. Said component or part 10 advantageously relates to a turbine component, such as a component applied in the hot gas path of a gas turbine (not explicitly indicated). Particularly, the component 10 may relate to a blade, vane, shroud, shield, such as heat shield, tip, segment, insert, injector, seal, transition, burner, nozzle, strainer, orifice, liner, distributor, dome, boost, cone, lance, plate, resonator, piston or any corresponding retrofit.

(5) In FIG. 1, the component 10 is advantageously depicted during its manufacture and only partly established. It is indicated that, after the deposition of a powder layer, e.g. with the aid of a deposition apparatus or recoater 30, an energy beam 21 is used to selectively melt the powder for the layerwise buildup of the component 10. A layer thickness of the layer may amount to LT, as indicated on the right in FIG. 1.

(6) Said energy beam 21 is advantageously emitted from an irradiation apparatus 20, such as an electron beam or laser source. After the local melting due to the energy beam 21, the material expediently solidifies in the final structure for the component 10.

(7) After a layer has been manufactured, the platform 1 is advantageously lowered by a distance corresponding to the layer thickness LT. Further, the deposition apparatus 30 advantageously distributes a further powder layer which may be moved from a stock or supply (not explicitly numerically indicated) of the respective powdery base material P as shown in the left of FIG. 1.

(8) The actual powder bed fusion process is advantageously carried out under an inert gas atmosphere or at least an atmosphere with reduced oxygen content in order to avoid significant oxidation or deterioration of powder in/or the component 10. Said inert gas or gas flow (not explicitly indicated) may be established in a laminar manner, e.g. with an inlet and an outlet in the build space. Additionally or alternatively, said inert gas may be used for purging or “inertising” only parts of the powder bed, e.g. a melt pool during the operation of the device.

(9) FIG. 2 shows an apparatus 100 in a schematic (at least partly) sectional view. The apparatus 100 is advantageously an unpacking apparatus and/or configured for removing an excess material P, advantageously an excess powder as a base material from an inside, a cavity or other passageways or spaces defined by the structure and/or design of the as-manufactured part 10.

(10) The apparatus 100 comprises a platform 1 for retaining the component (cf. reference numeral 10 in FIG. 2). This platform may be a table onto which the substrate plate 11 may be fixed or clamped or secured otherwise.

(11) The apparatus 100 further comprises a drive mechanism 2 which is coupled to the platform 1. Said drive mechanism 2 is configured to rotate the component 10 or deflect it, advantageously independently, around two orthogonal spatial directions, which are indicated by the horizontal axis X and the vertical Y-axis in FIG. 2. Preferably, said drive mechanism 2 is capable of rotating the platform 1 around the X-axis and the Y-axis with an unlimited angular deflection or degree of freedom. In other words, the platform may advantageously be rotated in an endless loop or at a multiplicity of revolutions such that very complicated and sophisticated powder escape turns and actuation is of the platform carrying or retaining the component may be applied in order to reliably remove the excess powder P from a cavity (not explicitly indicated) of the component 10.

(12) It is shown in FIG. 2 that a fairly complex and heavy component 10 is arranged, advantageously welded, to the substrate plate 11. The substrate plate 11 is in turn retained by the platform 1. The curved arrow is further indicated in FIG. 2 with numeral RP. Said arrow RP shall indicate a powder removal path of powder P which remained e.g. close to the substrate plate 11 and originated from powder bed based manufacture (cf. FIG. 1).

(13) To facilitate e.g. a rotation around the X-axis, a first motor M1 is provided by the drive mechanism 2. Motor M1 advantageously drives a driveshaft via a first worm gear or worm gear box WG1 such that the platform 1 may be angularly deflected or rotated by an angle α.

(14) To facilitate e.g. a rotation around the Y-axis, a second motor M2 is provided by the drive mechanism 2. Motor M2 advantageously drives a driveshaft via a second worm gear or worm gear box WG2 such that the platform 1 may be angularly deflected or rotated by an angle β.

(15) Said worm gear embodiments particularly allow for an infinite rotational movement, when the motors M1, M2 are continuously operated, respectively.

(16) Said worm gears WG1, WG2 are expediently functioning independently, wherein each worm gear is set up for the rotation of the platform 1 around one spatial direction each.

(17) As indicated in FIG. 2, said motors, drive shafts and worm gear (boxes) are advantageously arranged such that said independent control and movement can be implemented. To this effect, the second worm gear WG2 or its corresponding driveshaft (not explicitly indicated) is e.g. located axially (i.e. aligned with the X-axis), wherein the first worm gear (box) WG1 may be aligned with the Y-axis and/or parallel to a longitudinal axis of the component 10 orthogonal to the substrate plate 11.

(18) In the given exemplary embodiment of FIG. 2, the platform 1 may be mounted directly with a platform plane aligned perpendicularly with respect to the driveshaft of the second worm gear WG2. Further, the platform 1 is coupled and/or fixed to a lever of the first worm gear WG1.

(19) Of course, said motors M1, M2 can be controlled independently such that any superposition of said rotational movements may be chosen and implemented for very complex powder removal paths (cf. above). E.g. by way of these infinite rotational degrees of freedom around two linearly independent spatial directions (X, Y), every perceivable orientation of the component 10 may be implemented. Merely for the sake of simplicity only a vertically aligned orientation of a longitudinal axis of the component 10 (cf. X-axis) is indicated in FIG. 2. Any trapped powder may, thus, be removed from cavities (not explicitly indicated in FIG. 2) of the component 10, provided that tailored or intelligent controls and algorithms are applied for the control of the apparatus, the drive mechanism and/or the actuation means. The only it a may be the presence of adequately dimensioned openings of the cavities via access base material may escape from the component.

(20) If the component 10 is e.g. a burner component for a gas turbine, the escape routes calculated or simulated by which the powder P has to be removed, may be very complex and require the apparatus to be controlled with lots of tailored movements and actuations.

(21) The apparatus 100 advantageously further comprises a control unit 40. Via the control unit 40 the apparatus 100 may be controlled, e.g. computer-controlled. The control unit 40 may thus constitute or comprise a data processing unit.

(22) The apparatus 100 further comprises a housing 4. The housing 4 advantageously defines a working space WS. During the operation of the apparatus 100, the working space WS is expediently polluted, contaminated or exposed or fluidically connected to residual powder material P which is actually being removed from an inside of the component 10. Swirled powder dust or powder clouds may consequently pose significant ignition or explosion risks.

(23) During or after the powder removal in the working space WS, according to the embodiment shown in FIG. 2, the residual powder P may fall to the bottom of the working space WS and be collected in a funnel and/or collection tray 5.

(24) According to the present solution, the housing 4 seals the working space WS against the environment (not explicitly indicated) by means of seals 6. Said seals 6 may e.g. surround the drive shafts of the electrical motors M1, M2 for driving the respective worm gears.

(25) It is further shown in FIG. 2, that any electrical components for the drive mechanism and/or any further perceivable electrical components are arranged out of the working space WS in order to lower and most advantageously exclude any risk of ignition of powder clouds in the working space WS.

(26) The apparatus 100 further comprises an actuation means 3 for mechanically actuating the platform during a removal of the excess material P.

(27) The actuation means 3, is arranged inside the working space WS, and driven by a pressurised inert gas and without any electrical gear. This allows to minimise the risk of ignition and/or explosion of powder dust in the working space WS (cf. above).

(28) The actuation means 3 comprises a first vibration generator Vbr1 being configured for actuating the platform 1, the substrate 11 and/or base material P at a first frequency F1 corresponding frequency range.

(29) The actuation means 3 advantageously further comprises a second vibration generator Vbr2 being configured for actuating the platform 1, the substrate 11 and/or base material P at a second frequency F2 or corresponding frequency range.

(30) The second frequency (range) F2 is, advantageously, different from the first frequency (range) F1.

(31) The first vibration generator Vbr1 is advantageously a low frequency, high impact generator. The first frequency F1 may e.g. comprises or span frequencies from 1 mHz to 1 Hz.

(32) On the other hand, the second vibration generator Vbr2 is advantageously a high frequency, low impact generator. The second frequency F2 may comprise frequencies from 1 Hz to 10 kHz.

(33) Although the actuation means 3 is advantageously arranged inside the working space WS, no risk of explosion is provided by this embodiment of the actuation means 3, as the actuation means 3 is advantageously driven by a pressurised inert gas and without any electrical gear. Further, said actuation may be carried out in situ, i.e. directly at and in the vicinity of the platform 1, where the actuating effect is required.

(34) The apparatus 100 and all its components and features are advantageously configured to drive, i.e. move, actuate as well as rotate large masses, advantageously masses of more than 10 kg, advantageously more than 50 kg, or even larger masses such as masses in excess of 100 kg or more. Thus, said apparatus 100 may be applied in a very versatile way and without limitation of the used base material.

(35) The scope of protection of the invention is not limited to the examples given hereinabove. The invention is embodied in each novel characteristic and each combination of characteristics, which particularly includes every combination of any features which are stated in the claims, even if this feature or this combination of features is not explicitly stated in the claims or in the examples.