HIGH SPEED ROTARY ATOMIZER ASSEMBLY
FIELD OF THE INVENTION This invention relates to a support unit of a rotary atomizer for moving a bell coupled to the turbine device for coating a part.
BACKGROUND OF THE INVENTION A production paint application process where paint is applied to a substrate, such as, for example, a vehicle body passing through a paint booth, requires that paint be transferred from a paint tank to a paint tank. a paint applicator robot placed in the paint booth, where paint is applied by a rotary atomizer as an integral part of the paint applicator robot. Typically, the rotary atomizer includes a turbine device arranged in a housing, a rotating bell unit having an axis connected to a bell and disposed in and rotatable relative to the turbine device and the housing. The bell has a generally conical overflow surface between a central axial hole radially inwardly and an atomizing edge radially outwardly. At or near the atomizing edge radially outward, the angle of the overflow surface relative to the axis of the bell sharply decreases to form a lip adjacent the atomizing edge. The purpose of this lip is to generally direct the atomized paint more axially forward and reduce the radial dispersion. Typically, an air forming ring is attached to the turbine device to improve the distribution of the paint on the vehicle body being painted. The technique is replete with prior art designs of air forming rings for a rotary atomizer. U.S. Patent Nos. 5,775,598 to Takamaya et al; 5,727,735 issued to Baumann et al .; 6,189,804 and 6,623,561 issued to Vetter et al .; and U.S. Patent Publications Nos. 2005/0001077 and 2003/0010840 issued to Kon et al. U.S. Patent Publication No. 2005/0001077 issued to Kon et al., For example, discloses a rotary atomizer having a housing, a turbine device arranged in the housing, a bell unit disposed in and rotatable with relation to the turbine device. An air forming ring is arranged around the turbine device and is connected to the housing by a partially threaded fastener which extends to a hook for interconnecting the air forming ring with the housing. This design is complex and requires an additional component, such as said fastener for interconnecting the housing with the air forming ring. On the other hand, U.S. Patent No. 6,623,561 to Vetter et al. Discloses a rotary atomizer having a housing, a turbine device disposed in the housing, a bell unit disposed in and rotatable relative to the device. turbine. An air forming ring is arranged around the turbine device and between the turbine device and the housing. The air forming ring of U.S. Patent No. 6,623,561 issued to Vetter et al. Does not require additional components, such as, for example, a partially threaded fastener extending to a hook, described in the United States Patent Publication. United number 2005/0001077 of Kon and collaborators to interconnect the air forming ring with the housing. Therefore, the air forming ring and the turbine device described in U.S. Patent No. 6,623,561 to Vetter et al. Do not make constant surface-to-surface contact between the air forming ring and the turbine device. Furthermore, no prior art patent discloses an improved atomizer design having a better rigidly stabilized connection between the turbine device and the housing to maintain a fixed air gap between the shaft and a tube or line of paint extending to Through the shaft to keep the shaft at a fixed distance relative to the paint line when the shaft rotates around the axis. Thus, the purpose of the invention is to provide an improved design of the turbine device to eliminate at least one of said problems associated with the prior art atomizers. COMPENDIUM OF THE INVENTION An atomizer assembly of the present invention fluidly communicates with a source of fluid to coat a part, such as, for example, a body of a motor vehicle. The atomizer assembly includes a housing having at least one fluid line, i.e., a line of paint connected to the housing and extending therethrough, a turbine device having terminal ends and surrounding an axis and disposed in the housing. An atomizing hood unit has a shaft and a spray hood connected to the shaft and communicates fluid with the paint line to apply the paint to the body of the motor vehicle. The atomizing hood unit is disposed in the turbine device surrounding the shaft and being able to rotate about the axis and relative to the turbine device. The hood unit of the atomizer has terminal ends, one terminal end being exposed to the fluid source and the other terminal exposed to the bodywork of the motor vehicle being covered. The turbine device includes an annular wall extending outward from one of the terminal ends of the turbine device. The annular wall circumscribes the atomizing hood unit. The annular wall and the terminal end of the support define a seat for engaging the housing to provide a rigidly stabilized connection between the turbine device and the housing, thereby maintaining a fixed annular interval between the axis and the painting line extending to through the axis of the atomizing hood unit at a fixed distance relative to the paint line when the shaft rotates about the axis. A potential element is arranged around the support in the atomizing hood to concentrate the paint particles when the paint is applied to the body of the motor vehicle, a pushing device is arranged in the turbine device for interconnecting the turbine device and the element potential for a better continuous path and to provide constant surface-to-surface contact between the turbine device and the potential element when the fluid is applied to the part. An advantage of the present invention is to provide an annular wall extending outwardly of the turbine device by defining a seat for engaging the housing thereby forming a rigidly stabilized connection between the turbine device and the housing, which has been shown to maintain a fixed interval between the axis of the rotating bell unit and the paint line to maintain the axis at a fixed distance relative to the paint line in order to avoid contact between the paint line and the shaft.
Another advantage of the present invention is to provide the turbine device having a better surface-to-surface contact between the potential element and the turbine device in order to improve the ionization of the atomized fluid particles. BRIEF DESCRIPTION OF THE DRAWINGS Other advantages of the present invention will be readily appreciated as it is better understood by reference to the following detailed description considered in connection with the accompanying drawings wherein: Figure 1 illustrates a rotary atomizer in an arm robotic placed next to a vehicle body in a paint shop. Figure 2 is a cross-sectional view of a turbine device installed in a turbine housing. Figure 3 is an exploded perspective view of the turbine device shown in Figure 2. Figure 4 is an exploded perspective view of the turbine device. Figure 5 is a cross-sectional view of a neck portion of the turbine device. Figure 6 is an end view of one of the rim plates of the casing of the turbine device illustrating a brake nozzle and at least two inlets. Figure 7 is a cross-sectional and fragmented view of a pushing device disposed in the housing of the turbine device. And Figure 8 is a cross-sectional and fragmented view of the pushing device of Figure 7 shown in compressed mode and pushed against an air forming ring to make surface-to-surface contact. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to Figures 1 and 2, where like numbers indicate analogous or corresponding parts, an atomizer assembly of the invention is generally represented at 10. A paint recirculation system (not shown) supplies paint to a paint booth 12 where the paint is applied to a production part, such as, for example, a vehicle body 14. In a typical automobile assembly plant the vehicle body 14 is transported by transportation equipment 16 through of the paint booth 12 where the paint is applied to the vehicle body 14 and subsequently cured in a paint oven (not shown) as known to those skilled in the art. The paint is applied by automatic application equipment, such as a robotic device 18 which includes the atomizer assembly 10 connected to an arm 20 of the robotic device 18. Alternatively, the atomizer assembly 10 is operatively connected to an upper or lateral alternator (not shown). ).
With reference to Figures 2 to 4, the atomizer assembly 10 includes a housing, indicated generally at 22 in Figure 2, having a curved configuration. The housing 22 is defined by a plurality of removable components, one of these components, that is to say the central element 24, as shown in FIG. 2, surrounding an axis A. The central element 24 is arranged in the housing to engage at least a paint supply line or a supply unit 26 communicating fluidly with a paint source (not shown). The central element 24 has an inner surface 28 defined between an annular side wall 30 of the central element 24. A turbine device, generally represented at 40, is the real driving element of the high-speed atomizer assembly 10 and is disposed therein. central element 26. As shown well in Figures 3 and 4, the turbine device 40 includes a front plate 42, a neck portion, generally indicated at 44, and defining a tubular body 46 and a base plate 48 that it has a diameter greater than a diameter of the tubular body 46. The turbine device 40 includes a pair of central plates 50, 52 disposed between the front plate 42 and the neck portion 44. The central plates 50 and 52 and the base plate 48 they form a camera, partially represented at 54 in FIG. 5. An annular intermediate chamber 56 is defined by a cavity formed in one of the plates 50 and is covered by the other plate 52 to form the intermediate annular chamber 56. A first inlet 58 is defined in FIG. the annular intermediate chamber 56 for supplying fluid, such as, for example gas or air, to the annular intermediate chamber 56 from a fluid source (not shown). The turbine device 40 defines a proximal end 59 and a distal end 60. At least a second inlet 61 is defined in the annular intermediate chamber 56 to supply fluid to the annular intermediate chamber 56 thereby increasing the amount of fluid in the intermediate chamber annular 56 for the purpose of increasing the rotational speed of an atomizing hood unit, generally indicated at 62 and well represented in Figures 3 and 4. The atomizing hood unit 62 will be described in more detail as the description of the present invention. The atomizing bell unit 62 is rotated as more fluid is introduced through a plurality of nozzles, such as, for example, Lavalle nozzles 64, 66, and 68 defined in the center plate 52 as shown. Fig. 6. The nozzles 64 to 68 are exposed from the annular intermediate chamber 56 and are arranged asymmetrically with respect to the axis A. The nozzles 64 to 68 are spaced angularly and vertically with respect to the axis A to rotate the bell unit atomizer 62. Preferably, one of the nozzles 64 to 68 is defined between the first inlet 58 and the second inlet 61 defined in the central plate 52. The nozzles 64 to 68 move fluid in unison with the intermediate annular chamber 56 to facilitate the application fluid uniform to the atomizing hood unit 62. Preferably, the nozzles 64 to 68 are oriented in the circumferential direction in a range of an angle of approximately 13 Referring to the above, the first inlet 58 and the second inlet 61 discharge fluids axially into the annular intermediate chamber 56. Preferably, the first and second inlets 58 and 61 have a circular cross section with a diameter of 5 mm. The first inlet 58 and the second inlet 61 are exposed to the intermediate chamber 56 to discharge fluid from the intermediate chamber 56. As shown in Figure 6, the first and second inlets 58 and 61 are located in the upper half of the chamber annular intermediate 56, as shown well in Figure 6. A brake nozzle 69 is defined in the central plate 52 to move fluid to the hood unit of the atomizer 62 in a direction inverse to the angular direction of the fluid moved through the the nozzles 64 to 68 thereby decreasing the rotational speed of the hood unit of the atomizer 62.
As shown well in Figure 4, the front plate 42 includes connections for support air 80, a connection hole for rupture air 84, a pair of connection holes for turbine air or turbine air ducts 86, 88 , and a connecting hole for forming air 90. Said connecting holes 80 to 90 are connected independently or separately to the fluid source. The turbine air ducts 86, 88, which are independently connected to another fluid source (not shown), supply compressed air to a turbine wheel 102 of the atomizer bell unit 62 to move an axle 104 connected to the wheel 102. By using two ducts 86, 88 for the turbine air, the performance of the turbine device 40 is improved and controlled more accurately. Said connecting holes 80 to 90 are spaced radially around a stabilizing element defined by an annular wall 94. The annular wall 94 extends outwardly from the proximal end 59 of the turbine device 40 circumscribing the atomizing bell unit 62 to define a seat , generally indicated at 96 in FIG. 2, for engaging the central element 24 in order to form a rigidly stabilized connection between the turbine device 40 and the central element 24. The annular wall 94 includes a plurality of exhaust holes of air 98 defined radially in the annular wall 94 and at least a cut portion 100 defined therein. As is well illustrated in Figures 3 and 4, the shaft 104 of the spray hood unit 62 holds and moves a spray hood 108 arranged at one end 112 of the shaft 104. The turbine wheel 102 is rigidly connected and circumscribes the shaft 104 at another end 114 of the shaft 104. Multiple portions are cut in a U-shaped 115 at the end 114 of the shaft 104. Each portion cut in the shape of ü 115 is aligned with the cut portion 100 defined in the annular wall 94 to receive a fastener 117 extending through the housing 22 in order to prevent rotational movement of the shaft 104 during cleaning of the turbine device 40. The shaft 104 is hollow to receive the paint line 26 guided to its through and exposed through the hood 108 to the bodywork of the motor vehicle. The shaft 104 includes an annular groove 109 defined therein to form an air support. Preferably, the annular groove 109 is exposed to an air channel 119 defined in the neck portion 46 to receive the support air and move the support air to the annular groove 109 thereby distributing the support air uniformly along the shaft 104 for improving the alignment of the axial rotation of the shaft 104. The rigidly stabilized connection defined between the turbine device 40 and the central element 24 maintains a fixed interval between the paint line 26 and the axis 104 of the atomizing hood unit maintaining the axis 104 at a fixed distance relative to the paint line 26 when the axis 104 rotates about the axis A, as shown well in figure 2. This fixed interval avoids contact between the paint line 26 and the shaft 106 and reduces the chances of natural wear of the paint line 26 by the rotary shaft 104 at high speed. The shaft 104 is moved by the turbine air. A reflecting disc, indicated generally at 116, is attached to the turbine wheel 102 to monitor the rotational speed of the bell 108. The speed of the bell 108 presents an important parameter for atomization of the paint. The speed of the bell 108 is measured in the turbine device 40 using said reflector disk 116, an optical fiber cable (not shown), and an optoelectronic converter (not shown). The reflector disc 116 has four reflective surfaces 122 to 128 and four alternating black surfaces 130 to 136. This configuration provides four pulses of light reflected back to the fiber optic cable with each rotation of the axis 104. The optoelectronic converter changes these pulses of light to electrical signals that are processed by a speed transducer (not shown). The speed transducer compares the current speed of the axis 104 with the present value by means of the signals and consequently regulates the supply of the turbine air. A plurality of vanes 130 are connected and extend outwardly and axially of the turbine wheel 102 to receive support air. Each turbine blade 130 is curved, as shown in Figure 3. Alternatively (not shown), each turbine blade 130 is not curved and extends radially from the axis A. A second wheel 132 has a frusto-conical configuration and is connected to the shaft 104 below the blades. of turbine 130. The second wheel 132 includes a vortex-shaped outer surface 134 which produces air turbulence when the shaft 104 rotates about the axis. A potential element, such as, for example, an air shaping ring 140 provides a source of direct atomization of atomized paint particles. The air forming ring 140 is disposed around one of the terminal ends 118 in the neck portion 46 of the turbine device 40 around the bell 108. The air forming ring 140 is known to those skilled in the art and is designed to concentrate the paint when the paint is applied to the body 14 of the motor vehicle by injecting air from annular channels 141 defined in the neck portion 46 to the bell 108 through annular holes 143. To improve contact between the neck portion 46 and the air forming ring 140, a pushing device, generally indicated at 150, is disposed in the neck portion 46 of the turbine device 40 for interconnecting the turbine device 40 with the air forming ring 140 with the In order to improve the continuity of the path and to make constant contact from surface to surface between the turbine device 40 and the air forming ring 140. In a As an alternative embodiment of the present invention, the potential element is defined by a source of indirect atomization, such as, for example, a plurality of electrostatic probes (not shown). The pushing device 150 is disposed in a cavity 152 defined in the neck portion 46. The pushing device 150 includes a tubular housing 154, a ball 156, and a spring 158 extending from the cavity 152 to the ball 156 for moving the ball 156 away from the tubular housing 154 when the air forming ring 140 is arranged around the neck portion 46 of the turbine device 40. The atomizer assembly 10 has an air-tight enclosure. To conserve the air within the atomizer assembly 10 a cover 180 is mechanically connected to the annular wall 30 of the central element 24 which extends between the central element 24 and the air forming ring 140. The turbine device 40 includes a plurality of gaskets. tori-cages 160 arranged in respective annular grooves 162. To hold the front plate 42, the neck portion 44, the base plate 48, the central plates 50, 52, at least one centering pin 166 and a pair of screws 168 extends through the front plate 42, the neck portion 44, the base plate 48, the central plates 50, 52 for holding together the front plate 42, the neck portion 44, the base plate 48, the central plates 50, 52. Although the invention has been described with reference to an exemplary embodiment, those skilled in the art will understand that various changes can be made and that its elements can be replaced by equivalents without departing from the scope of the invention. nce of the invention. In addition, many modifications can be made to adapt a particular situation or material to the ideas of the invention without departing from its essential scope. Therefore, it is intended that the invention not be limited to the particular embodiment described as the best contemplated way of practicing this invention, but that the invention will include all embodiments falling within the scope of the appended claims.