A rotary sprayer comprising a rotating bowl and magnetic coupling means, and a method for assembling and / or disassembling such a sprayer

Abstract

Rotary sprayer comprising a rotating bowl and magnetic coupling means, and method for mounting and / or dismounting such a sprayer. The present invention relates to a rotary coating product sprayer (2) comprising a main body (4) and a bowl (8) driven in rotation by a rotating member (10), about an axis of rotation (A2) defined by the main body. The bowl is equipped with first magnetic coupling means (82) adapted to cooperate with complementary second magnetic coupling means (14) fixed on a non-rotating part (6) of the sprayer (2). The first and second coupling means are adapted to exert a force at least partially axial with respect to the axis of rotation (A2) of the bowl (8), this force inducing the rotational coupling of the bowl with the rotating member. The second magnetic coupling means (14) are carried by an air inlet skirt (6) attached to the main body (4). Figure for the abstract: Figure 1

Description

Title of the invention: Rotary sprayer comprising a rotating bowl and magnetic coupling means, and method of mounting and / or dismounting such a sprayer

[0001] The present invention relates to a rotary sprayer for coating product comprising a main body and a bowl driven in rotation about an axis of rotation defined by the main body. The present invention also relates to a method of mounting and / or dismounting a sprayer of this type.

[0002] It is known from WO2005 / 082542A1 to mount a bowl on a rotary sprayer by associating first and second magnetic coupling means fixed respectively on the bowl and on a non-rotating part of the sprayer, which makes it possible to exert a generally axial force, such as to induce a rotational coupling of the bowl and a drive member, such as the rotor of a turbine or a shaft driven by such a rotor. This equipment is generally satisfactory.

[0003] On the other hand, it is known to equip a rotary sprayer with an air supply skirt which makes it possible to distribute, near the bowl, an air flow for guiding or shaping a cloud of droplets of coating product leaving the edge of the bowl. The second magnetic coupling means are then often arranged on a central part of a main body of the sprayer, opposite a central opening of the air supply skirt in which the bowl is engaged to cooperate with these rotational drive means. In this case, the air supply skirt must be mounted on the main body before positioning the bowl which must be precisely positioned, by hand, opposite the second magnetic coupling means.Conversely, during a maintenance operation, the bowl must be separated from the main body, then the skirt must be separated from this body, during two successive manual operations, which are difficult to carry out in an environment not conducive to handling, such as a paint booth.

[0004] Furthermore, in some applications, the bowl is of relatively modest size, to the point that it is difficult to hold, which leads to a risk of dropping it when handling it by hand. In particular when dismantling the bowl and the air supply skirt, if the operator acts on the skirt before removing the bowl, there is a strong chance of dropping the bowl, the edge of which will then probably be damaged.

[0005] With these materials, the assembly and disassembly of the bowl and the air intake skirt are complex operations that are difficult to automate.

[0006] It is these drawbacks that the invention more particularly intends to remedy by proposing a new rotary sprayer of coating product in which the mounting an air intake skirt and a bowl on a main body is made easier, this mounting being able, to a large extent, to be automated.

[0007] To this end, the invention relates to a rotary sprayer for coating product comprising a main body and a bowl driven in rotation by a rotating member, around an axis of rotation defined by the main body, the bowl being equipped with first magnetic coupling means capable of cooperating with second complementary magnetic coupling means fixed on a non-rotating part of the sprayer for coating product, the first and second coupling means being capable of exerting a force at least partially axial relative to the axis of rotation of the bowl, this force inducing the rotational coupling of the bowl with the rotating member, characterized in that the second magnetic coupling means are carried by an air supply skirt attached to the main body.

[0008] Thanks to the invention, the first and second magnetic coupling means make it possible to assemble the air intake skirt and the bowl in the form of a subassembly which can be handled as a unit when it is mounted on the main body, or when it is dismounted. This subassembly is larger than the bowl alone, and is therefore easier to handle. It is less likely to be dropped. Furthermore, since the first and second coupling means correctly position the bowl relative to the air intake skirt, correctly mounting this skirt on the main body guarantees good positioning of the bowl relative to this body, and therefore relative to the rotating member which drives the bowl in rotation.

[0009] According to advantageous but not mandatory aspects of the invention, such a sprayer may incorporate one or more of the following features taken in any technically admissible combination. - The second magnetic coupling means are mounted on, or formed by, an internal collar of the air intake skirt, resting on a front face of the main body. - The first magnetic coupling means are formed by a ferromagnetic part of the bowl and the second magnetic coupling means are formed by at least one permanent magnet. - The first magnetic coupling means are formed by at least one permanent magnet and the second magnetic coupling means are formed by a ferromagnetic part of the air supply skirt. - The sprayer includes a magneto-pneumatic or magneto-hydraulic system which includes • a magnetic device for attaching the air intake skirt to the main body; and • a pneumatic or hydraulic mechanism for locking and tightening the air intake skirt on the main body. - The magnetic attachment device is configured to exert, between the air supply skirt and the main body, an axial magnetic force, parallel to a longitudinal axis of the sprayer, with a first intensity, while the pneumatic or hydraulic clamping mechanism is configured to exert between the air supply skirt and the main body an axial mechanical force, parallel to the longitudinal axis of the sprayer, with a second intensity and while the second intensity is strictly greater than the first intensity. - The sprayer comprises seals arranged between the air supply skirt and the main body and the seals compressed by the mechanical force exerted by the pneumatic or hydraulic clamping mechanism isolate the conforming air circulation ducts from the outside of the sprayer. - The air intake skirt is provided with screw reliefs on complementary reliefs provided on the main body. - The air intake skirt is clamped to the main body by a magnetic force exerted between a part of the main body and a part of the air intake skirt.

[0010] According to a second aspect, the invention relates to a method of mounting and / or dismounting a coating product sprayer as mentioned above, in which - when assembling the sprayer, • in a first assembly step, the air intake skirt and the bowl are assembled and held together by a magnetic force between the first and second magnetic coupling means; • in a second assembly step, a sub-assembly formed from the air intake skirt and the bowl is attached in one operation to the main body; - when dismantling the sprayer, • in a first disassembly step, the subassembly formed by the air intake skirt and the bowl is separated from the main body in one operation; and • in a second disassembly step, the air intake skirt and the bowl are separated from each other, against the magnetic force between the first and second magnetic coupling means.

[0011] The invention will appear more clearly on reading the description which follows, given solely by way of non-limiting example and made with reference to the appended drawings in which: - [Fig.l] [Fig.l] is a partially exploded longitudinal section of a pul verifier conforming to a first embodiment of the invention; - [Fig.2] [Fig.2] is an exploded perspective longitudinal section of a magneto-pneumatic system belonging to the sprayer of [Fig.l]; - [Fig.3] [Fig.3] represents, on two inserts A) and B), the sprayer of [Fig.l] during a first sub-step of assembly on a main body of a sub-assembly comprising an air supply skirt and a bowl, insert B) being a larger scale view of detail B on insert A); - [Fig.4] [Fig.4] is a view similar to [Fig.3], during a second sub- step of the assembly process; - [Fig.5] [Fig.5] is a view similar to [Fig.3], during a third sub-step of the assembly process; - [Fig.6] [Fig.6] is a view similar to [Fig.3], during a fourth sub-step of the assembly process; - [Fig.7] [Fig.7] is a section similar to [Fig.l], for a sprayer in accordance with a second embodiment of the invention; - [Fig.8] [Fig.8] is a section similar to [Fig.1], for a sprayer according to a third embodiment of the invention; and - [Fig.9] [Fig.9] is a section similar to [Fig.l], for a sprayer in accordance with a fourth embodiment of the invention.

[0012] The coating product sprayer 2 shown in Figures 1 to 6 comprises a main body 4 formed by the assembly of an external part 42, an internal part 44 and a base 46.

[0013] For example, the coating product is a liquid paint, primer or varnish intended to be applied to a body or component of a motor vehicle.

[0014] Screws 48 secure the parts 42, 44 and 46 of the main body. These screws 48 protrude relative to a front face 428 of the external part 42.

[0015] The sprayer 2 is of the electrostatic type with internal charge and comprises a high-voltage unit, not shown, configured to bring the coating product sprayed by the sprayer 2 to a given electrical potential.

[0016] A2 is a longitudinal axis of the sprayer 2.

[0017] A front side of the sprayer 2 or of a component of this sprayer is defined as a side facing a part to be coated, during use of the sprayer 2, and a rear side as a side facing away from the front side. In the figures, the front of the sprayer 2 is facing upwards and the rear is facing downwards.

[0018] An air supply skirt 6 is mounted on the main body 4 in the assembled configuration of the sprayer 2. This air supply skirt 6 comprises a skirt body 62 and a sleeve 64 screwed onto the skirt body 62.

[0019] Alternatively, the skirt body 62 and the sleeve are secured by crimping, welding and / or collage.

[0020] The connection between the skirt body 62 and the sleeve 64 takes place at a front end 641 of the sleeve.

[0021] The sleeve 64 is made of a ferromagnetic material, for example steel.

[0022] A spray bowl 8 also belongs to the sprayer 2 and is intended to be driven in rotation, around the longitudinal axis A2, by a turbine of which the rotor 10 is denoted 10. The stator of the turbine is constituted by the internal part 44 of the main body 4.

[0023] The bowl 8 defines a male frustoconical surface 88, converging towards the rear, while the rotor 10 defines a female frustoconical surface 108, diverging towards the front and generally complementary to the male frustoconical surface 88.

[0024] An annular magnet 14 is carried by an internal radial collar 649 of the air supply skirt 6. More precisely, the magnet 14 is arranged in a groove 650 formed in the internal radial collar 649 and oriented towards the front of the air supply skirt 6.

[0025] In the mounted configuration of the bowl 8 on the air supply skirt 6, and before mounting the air supply skirt on the main body 4, an annular surface 82 of the bowl 8, which is made of a ferromagnetic material, comes opposite the permanent magnet 14, which has the effect of securing together the parts 6 and 8 which then constitute a subassembly 22, unitary and easy to handle when it is placed on the sprayer 2 or when it is removed.

[0026] Alternatively, and as shown for the third embodiment, only a portion of the bowl 8 which defines the annular surface 82 is made of ferromagnetic material, for example in the form of a steel ring attached to the bowl 8 which is, for example, made of aluminum.

[0027] The ferromagnetic portion of the bowl, which defines the surface 82, forms first magnetic coupling means. The magnet 14 forms second magnetic coupling means. When the air supply skirt 6 equipped with the bowl 8 is mounted and immobilized on the main body 4, the first and second magnetic coupling means 82 and 22 cooperate in order to press the surface 88 of the bowl 8 against the surface 108 of the rotor 10, which secures the bowl and the rotor in rotation around the axis of rotation A2.

[0028] The sprayer 2 also comprises an injector 16 of coating product whose downstream end 162 penetrates into a central bore 84 of the bowl 8, in the mounted configuration of this bowl on the turbine rotor 10.

[0029] A cover 18 is mounted around the main body 4 and protects it against splashes of coating product.

[0030] The skirt body 62 is equipped with several channels 622 which pass through it from one end to the other. part, in a direction parallel to the longitudinal axis A2 in the mounted configuration of the air supply skirt 6 on the main body 4, and which each supply an outlet orifice 624 through which air jets can be directed towards a cloud of coating product leaving an edge 86 of the bowl 8, in order to shape this jet of coating product and / or to direct it towards an object to be coated. The orifices 624 are provided on a circular front face 626 of the skirt body 62.

[0031] The skirt body 62 defines a hollow housing 628 in which a front portion of the external part 42 of the main body 4 is received in the mounted configuration of the air supply skirt 6 on the main body 4. The hollow housing 628 is provided on the rear of the skirt body 62.

[0032] The external part 42 of the main body 40 comprises ducts 422 for conveying air towards the air supply skirt 6. These channels 422 are supplied with air by channels 442 which extend essentially in a plane different from that of figures 1 and 3 to 6 and of which only the downstream ends are visible in these figures.

[0033] The bottom 628a of the hollow housing 628 is equipped with two annular grooves 628c and 628d which serve as distributors to supply two groups of conduits 622 from the outlets 424 of the conduits 422. To ensure sealing against the passage of air between the conduits 422 and the grooves 628c and 628d, O-rings 20 are arranged in annular grooves 426 formed on the front face 428 of the external part 42 of the main body 4, that is to say in an interface zone between the main body 4 and the skirt 6. These O-rings 20 are intended to bear against the bottom 628a of the hollow housing 628 and to be compressed.

[0034] In the example of the figures, the O-rings 20 and the annular grooves 426 are concentric and three in number. In a variant not shown, the number and / or the shape of the O-rings 20 and the annular grooves 426 are different.

[0035] The sleeve 64 is intended to be engaged in a central housing L2 of the sprayer 2 which is defined, radially to the longitudinal axis A2, between the external part 42 and the internal part 44 of the main body 4.

[0036] 642 denotes the rear edge of the sleeve 64, that is to say the edge of this sleeve opposite the skirt body 62. 644 denotes the end of the sleeve 64 which is closest to the rear edge 642. The rear edge 642 delimits the rear end 644 opposite the skirt body 62. The rear end 644 is opposite the front end 641 of the sleeve 64.

[0037] S64 denotes the external radial surface of the sleeve 64. This external radial surface is provided with a peripheral groove 646 which forms a hollow housing on the outside of the sleeve 64. 646a denotes the rear edge of the peripheral groove 646, that is to say the edge of this groove closest to the end 644 of the sleeve 64.

[0038] We note 647 an external peripheral rib of the sleeve 64 which separates the groove pe peripheral 646 of the end 644. We note 647a the rear edge of this rib, that is to say the edge of this rib closest to the end 644 of the sleeve 64.

[0039] A magneto-pneumatic system 100 is provided in the central housing L2 to ensure attachment of the subassembly 22 to the main body 4, as well as clamping of the skirt 6 on this main body. The magneto-pneumatic system 100 comprises a magnetic attachment device 100A and a pneumatic clamping mechanism 100B of the air supply skirt 6 on the main body 4.

[0040] The attachment, obtained by means of the magnetic attachment device 100A, makes it possible to ensure that the air supply skirt 6 equipped with the bowl 8 remains in position on the main body 4, including when the latter is moved by a multi-axis robot or a reciprocator on which the sprayer is mounted. The movements of the sprayer induce accelerations on the air supply skirt 6 and on the bowl 8, which could have the effect of driving the sleeve 64 out of the central housing L2. The magnetic attachment force is sized to resist these accelerations.

[0041] The clamping force makes it possible to finalize the positioning of the air supply skirt 6 on the main body 4 and to compress the O-rings 20, thus ensuring the sealing of the circuit supplying the outlet orifices 624 with air for shaping the cloud of coating product.

[0042] The magneto-pneumatic system 100 extends along a longitudinal axis A100 which coincides with the longitudinal axis A2 of the sprayer 2 in the mounted configuration of the magneto-pneumatic system 100 in the sprayer 2.

[0043] The magneto-pneumatic system 100 comprises a cap 102 immobilized on the main body 4 by screws which pass through one or more tabs 102a provided on the outside of the cap 102. One of these screws is represented by its axis line 103 in [Fig.2],

[0044] The cap 102 defines an annular volume VI02 centered on the longitudinal axis A100 and which is bordered by an internal radial wall 102b and an external radial wall 102c.

[0045] A passage 102d is provided in the thickness of the external radial wall 102c and makes it possible to fluidically connect a conduit 446 provided in the internal part 44 of the main body 4 and the volume V102.

[0046] On the other hand, the internal wall 102b of the cover 102 ends with a chamfered edge 102e facing the volume V102 and converging towards the longitudinal axis A100 opposite the bottom 102f of the volume V102, that is to say in the direction of the rear of the cover 102.

[0047] The magneto-pneumatic system 100 also comprises a cup 104 placed on the rear bottom of the central housing L2. In the example of the figures, the bottom of the central housing L2 is opposite its front mouth and delimited by the internal part 44.

[0048] The magneto-pneumatic system 100 also comprises an annular piston 106 equipped with two sealing segments 107a and 107b. In the example, the sealing segments are made by two O-rings received in two peripheral grooves 106a and 106b, respectively external and internal, formed on the piston 106. The O-rings 107a and 107b are not shown in [Fig.l], which allows the grooves 106a and 106b to be better visualized.

[0049] Alternatively, the sealing segments are formed by lip seals. According to another alternative, they are mounted on the walls of the cap 102 opposite the piston 106.

[0050] The piston 106 is movable, parallel to the axes A2 and A100 combined, while being partially engaged in the volume V102 of the cap 102. Due to the partial engagement of the piston 106 in the housing V102 and the bearing surface of the sealing segments 107a and 107b against the walls 102c and 102b, a sealed chamber of variable volume C100 is defined between the elements 102 and 106. This chamber of variable volume C100 is supplied with pressurized air coming from the conduit 446 through the passage 102d. Means not shown, such as a source of pressurized air, a proportional valve and a purge valve make it possible to supply the chamber of variable volume C100 with pressurized air or to expose it to the open air, depending on a sequence of assembly or disassembly of the skirt 2 on the main body 4.The pressure of the air present in the duct 446 is controlled independently of the pressure of the drive air of the rotor 10 and the pressure of the skirt air in the ducts 442.

[0051] Alternatively, a portion of the drive air of the rotor 10 may be diverted to the duct 446. In this case, the variable volume chamber C100 may be supplied with pressurized air as soon as the turbine is in operation. According to another alternative, the duct 446 may be supplied with pressurized air from air used in the sprayer 2 for another function, for example from the skirt air circulating in the ducts 442.

[0052] The piston 106 also defines volumes V106 for receiving balls 108 which constitute members for engaging the piston 106 with the external peripheral groove 646 of the sleeve 64.

[0053] Advantageously, a ball 108 is mounted in each volume V106.

[0054] Each ball 108 is received in a volume V106 from which it may or may not protrude through an opening 0106 which constitutes the outlet of each volume V106 on the internal peripheral surface S106 of the piston 106.

[0055] Each volume V106 is defined, on its side opposite its opening 0106, by a surface S106 converging towards the front in the direction of the longitudinal axis A100 and inclined relative to this longitudinal axis by an angle of zero, preferably between 15° or 60°, more preferably between 30° and 50°.

[0056] The surfaces S106 of the different volumes V106 constitute cam surfaces for guiding the balls 108.

[0057] The magneto-pneumatic system 100 also comprises a support 110 which is also annular in shape centered on the longitudinal axis A100 and which is formed of a solid body 110a and a profile 110b, both made of a ferromagnetic material. The parts 110a and 110b of the support 110 are secured together by any suitable means, in particular by gluing, crimping and / or welding.

[0058] Alternatively, the support 110 is in one piece.

[0059] The support 110 is equipped with position indexing pins 110c, around the longitudinal axis A100, with respect to the piston 106.

[0060] The support 100 is also equipped with stops 110d intended to engage in the volumes V106 from the rear of the piston 106, to hold the balls 108 in position in these volumes.

[0061] The support 100 carries an annular permanent magnet 112 which is arranged on the internal radial side of the support 100. In the example, the permanent magnet is secured to the profile 110b, for example by gluing.

[0062] On the other hand, the support 100, more particularly its body 110a, defines a first frustoconical internal surface S110, centered on the longitudinal axis A100 and converging in the direction of the piston 106, and a second frustoconical internal surface S' 110, centered on the longitudinal axis A100 and diverging in the direction of the piston 106.

[0063] The magneto-pneumatic system 100 also comprises a plane spring 114 which forms an elastic member for returning the piston 106, and preferably the support 110, forward.

[0064] The flat spring 114 is formed by a steel blade. The use of a flat spring such as that shown in the figures has the advantage of allowing a relatively large axial stroke of the piston 106, while the axial size of the spring 114 is minimal.

[0065] Alternatively, the flat spring 114 can be replaced by another elastic member, in particular an elastomer block or a spiral spring.

[0066] A sprayer mounting method 2 is now explained.

[0067] In a first step, the subassembly 22 is formed by engaging the bowl 8 in the central opening 06 of the air supply skirt 6, until the magnet 14 and the surface 82 provide magnetic clamping between the elements 6 and 8. This step can be carried out in a workshop, in an environment suitable for precise work.

[0068] Then, in a second step, the subassembly 22 is mounted, that is to say attached in one operation, on the main body 4, as explained below. This step can take place on the site of use of the sprayer 2, for example a paint booth.

[0069] This assembly takes place by an axial translational movement of the subassembly 22, parallel to the longitudinal axis A2. This axial translational movement is represented by the arrow T in Figures 1 and 3 to 6. No other movement of the air supply skirt 6, therefore of the subassembly 22, is necessary to mount them on the main body 4.

[0070] Thus, the mounting of the subassembly 22 on the main body 4 results exclusively from a relative translational movement between these elements of the sprayer 2.

[0071] In a first sub-step of the second step shown in [Fig. 3], the sub-assembly 22 is aligned on the axis A2 and brought closer to the main body 4. In this step, the rear end 644 of the sleeve 64 is engaged in the central housing L2, without being in contact with the components of the magneto-pneumatic system 100.

[0072] Continuing the assembly of the subassembly 22 on the main body 4 brings the sleeve 64 to the sub-step shown in [Fig.4], where its rear end 644 bears by its edge 642 against the permanent magnet 112, while the edge 647a bears against the surface S' 110, which avoids plastic deformation of the end 644 at the end of travel.

[0073] In this sub-step, a closed magnetic flux FM is established through the rear end 644 of the sleeve 64, through the parts 110a and 110b of the support 110 and through the magnet 112, which has the effect of securing, by an axial magnetic attraction force, the air supply skirt 6 with the support 110, which is retained in position in the central housing L2 since its movements are limited between the cap 102 and the cup 104. Thus, the entire sub-assembly 22 is secured to the support 110. The axial magnetic attraction force between the parts 12 and 64 is parallel to the longitudinal axis A2, preferably centered on this axis, and results in the air supply skirt 6, and therefore the sub-assembly 22, being attached to the main body. This effort is therefore an effort to hook these pieces together.

[0074] The permanent magnet 112 is chosen to exert on the sleeve 64 a magnetic attachment force of sufficient intensity to retain the subassembly 22 in position on the main body 4, including when the latter is moved, for example when it is mounted on the wrist of the arm of a multi-axis robot or on a reciprocator, which subjects the subassembly 22 to these accelerations potentially directed in a direction of extraction of the sleeve 64 relative to the central housing L2.

[0075] In practice, the magnetic attachment force exerted by the permanent magnet on the sleeve has an intensity II of between 10 and 20 daN, preferably of the order of 15 daN, which allows effective attachment of the air supply skirt 6, therefore of the subassembly 22, to the main body 4. On the other hand, the relatively moderate value of this intensity II of the magnetic attachment force limits the risks of injury by pinching of an operator when the latter presents the subassembly 22 and engages the sleeve 64 in the central housing L2.

[0076] In the sub-step of [Fig. 4], the sub-assembly 22 is attached to the main body 4 by means of the magnetic force, but the bottom 628a of the hollow housing 628 remains spaced from the front face 428 of the external part 42, by a non-zero axial distance d8, this distance d8 being measured parallel to the longitudinal axis A2. In particular, in this sub-step, the seals 20 are not compressed and the seal between the air circuits, formed by the ducts 422 and 622 and the grooves 628c and 628d, is not ensured with respect to the outside.

[0077] In the steps and sub-steps of Figures 1, 3 and 4, the spring 114 exerts on the support 110 a force of separation relative to the cup 104, which has the effect of engaging the stops HOd in the different volumes V106, to the point that these stops 110d press on the balls 108 which themselves press on the cam surfaces S106 of the piston 106, which has the effect of pushing the latter towards the bottom 102f of the volume VI02. The variable volume chamber C100 then has a minimum volume visible in particular at the insert B) of [Fig.3].

[0078] In this position, each ball 108 bears against the chamfered edge 102e of the cap 102, so that it is retained in position in the corresponding volume V106 without projecting radially from the wall 102b, in a direction radial to the longitudinal axis A100 and centripetal. Under these conditions, the balls 108 do not oppose the sliding of the sleeve 64 in the central housing L2, in particular during the succession of the steps of FIGS. 1, 3 and 4. In particular, in the sub-step of [Fig. 4], the balls 108 are not engaged in the external peripheral groove 646.

[0079] From the sub-step of [Fig. 4], the passage 102d is supplied with pressurized air, which is represented by the arrow A in Figures 4 to 6. This has the effect of pressurizing the variable volume chamber C100, which expands, i.e. dilates, in the direction of the cup 104, as is apparent from the comparison of Figures 4 and 5. This axial expansion of the chamber C100 results from an axial displacement, parallel to the longitudinal axis A2, of the piston 106 in the direction of the cup 104, represented by the arrow D in Figures 5 and 6, this displacement being due to the difference between the pressure prevailing inside the variable volume chamber C100 and the external atmospheric pressure.

[0080] This movement D of the piston 106 has the effect of moving the different balls 108 in the direction of the cup 104, therefore the bottom of the central housing L2, which then become offset relative to the chamfered edge 102e of the wall 102b, this edge then no longer opposing a centripetal radial movement of the balls 108 through the openings 0106. However, taking into account the inclined nature of the cam surfaces S106 of the different volumes V106, the movement of the piston 106 in the direction of the cup 104 has the effect of exerting on the different balls 108 a centripetal force relative to the longitudinal axis A2, represented by the arrow F in [Fig.5] and directed towards the external peripheral groove 646. Thus, the air supply to the chamber C100 makes it possible to tighten different balls 108 around the sleeve 64, by engaging them, that is to say by making them penetrate at least partially, into the external peripheral groove 646. The balls 108 therefore constitute members for engaging the piston 106 with the external relief of the sleeve 64 constituted by the peripheral groove 646.

[0081] During the succession of the sub-steps of figures 4 and 5, the balls 108 push the support 110 towards the cup 104, against the elastic force exerted by the spring 114, which has the effect of axially separating the spring 112 and the end 644 of the sleeve 64. In other words, in the sub-step of [Fig.5], the rear edge 642 of the sleeve 64 is no longer in abutment against the magnet 112 and the edge 647a is no longer in abutment against the surface S' 110. This is not a problem since the balls 108 engaged in the external peripheral groove 646 then effectively retain the sleeve 64 in the central housing L2.

[0082] At the end of the sub-step of [Fig.5], the value of the distance d8 has decreased compared to its value in the sub-step of [Fig.4], but this value remains non-zero.

[0083] The continued supply of pressurized air to the variable volume chamber C100 through the passage 102d has the effect of continuing the movement of the piston 106 towards the cup 104, against the elastic force exerted by the spring 114, in the direction of the arrow D in [Fig. 6]. During this movement, the balls 108 come to bear against the rear edge 646a of the external peripheral groove 646 and transmit to the sleeve 64 the movement force which they undergo due to the movement of the piston 106 in the direction of the arrow D. Thus, the sleeve 64 is moved at the same time and over the same stroke as the piston 106, towards the bottom of the central housing L2, which is represented by the movement arrow D' in [Fig. 6].

[0084] This movement D' of the sleeve 64 inside the central housing L2 has the effect of firmly pressing the bottom 628a of the hollow housing 628 against the front face 428 of the external part 42 of the body 4 by compressing the seals 20, which fluidly isolates the conduits 422 and 622 and the grooves 628c and 628d from the outside. In other words, the pneumatic mechanism 100B exerts, on the sleeve 64 and by means of the balls 108, an axial mechanical clamping force, parallel to the longitudinal axis A2, which firmly presses the bottom 628a of the hollow housing 328 of the air supply skirt 6 against the front face 428.

[0085] Thus, the positioning and immobilization of the subassembly 22 on the main body 4 is carried out in two stages thanks to the magneto-pneumatic system 100. The pneumatic mechanism 100B is therefore also a mechanism for locking the subassembly 22 on the main body 4.

[0086] At the end of this installation, the bowl 8, which is integral with the air supply skirt 6 due to the interaction of the first and second coupling means 82 and 14, is pressed, by a magnetic force El parallel to the axis of rotation A2 and exerted by these coupling means, against the rotor 10, to the point that the friction forces between the surfaces 88 and 108 secure the bowl and the rotor in rotation around the axis of rotation A2.

[0087] Here, the force El is purely axial relative to the axis of rotation A2. In a variant of the invention not shown, the force El is partially axial relative to this axis of rotation, that is to say inclined relative to it, as envisaged in WO2005 / 082542A.

[0088] As the bowl 8 is correctly positioned on the air supply skirt 6 due to the cooperation of the magnetic coupling means 82 and 14, bringing the subassembly 22 into the position of [Fig. 6] ensures that, in this position, the bowl is correctly positioned relative to the rotor 10, in particular at the interface between the surfaces 88 and 108. The bowl 8 is then ready to be driven by the rotor 10.

[0089] When the turbine is operating, that is to say when the rotor 10 rotates around the axis of rotation A2, an air bearing is created between the surface 82 and the magnet 14 by injecting an air flow between these parts, according to the technique of WO2005 / 082542A1. The rotor 10 can thus drive the bowl 8 in rotation, around the axis of rotation A2.

[0090] The mechanical attachment device 100A, which comprises the elements 110 and 112, makes it possible to hold the subassembly 22 in position on the body 2 before the pneumatic clamping mechanism 100B, which comprises the elements 102, 106, 108 and 110, is used by supplying the variable volume chamber C100 with pressurized air to effectively clamp the air supply skirt 6, therefore the subassembly 22, in place on the main body 4, in particular by compressing the seals 20. The cup 104 and the spring 114 are accessories of the mechanical attachment device 100A and of the pneumatic clamping mechanism 100B within the magneto-pneumatic system 100.

[0091] The mechanical clamping force obtained by means of the pneumatic clamping mechanism 100B has an intensity 12 strictly greater than the intensity of the magnetic force mentioned above.

[0092] For example, the mechanical force obtained with the pneumatic clamping mechanism 100B may have an intensity of between 80 and 200 daN, preferably between 100 and 150 daN, more preferably of the order of 120 daN.

[0093] When it is necessary to disassemble the subassembly 22 from the main body 4, the supply of pressurized air to the variable volume chamber C100 is stopped and the passage 102d is exposed to the open air. The spring 114 then pushes the support 110, the balls 108 and the piston 106 towards the bottom 102f of the volume VI02, reducing the volume of the variable volume chamber C100.

[0094] The balls 108 then come into abutment against the chamfered edge 102e of the wall 102b, which has the effect of returning them towards the interior of the volumes V106, extracting them from the external peripheral groove 646. In other words, the balls 108 are no longer engaged with the external peripheral groove 646. Thus, the elastic force exerted by the spring 114 tends to return the piston to a position in which the balls 108 can be released from the external peripheral groove 646 of the sleeve 64.

[0095] By being pushed back by the spring 114, the support 110 carries with it the magnet 112 which comes into contact with the rear edge 642 of the sleeve 64, which has the effect of reactivating the magnetic attachment force between the sleeve 64 and the magnet 112. The magneto-pneumatic system 100 is then in a configuration similar to that of [Fig. 4] where the seals 20 are no longer compressed and where the subassembly 22 remains attached to the main body 4 by the magnetic force resulting from the magnetic flux FM represented by the arrows F. The subassembly 22 is reliably retained on the main body 4, for the reasons explained above.

[0096] It is then possible to extract the subassembly 22 during a first disassembly step, by exerting an axial force in a direction opposite to that of the arrow T in FIGS. 1 and 3 to 6.

[0097] In this regard, it is possible to use a disassembly tool not shown for this purpose.

[0098] Then, during a second disassembly step, the bowl 8 is separated from the air supply skirt 6, against the magnetic force between the magnet 14 and the surface 82. Like the first step of the assembly method, this second step of the disassembly method can be carried out in a workshop, in an environment suitable for precise work.

[0099] The structure of the subassembly 22 and of the magneto-pneumatic system 100 of the invention is compatible with the installation of the subassembly 22 on the main body 4 by means of a robot, as well as with its removal by means of a robot. Thus, according to a particular aspect, the present invention makes it possible to automate the assembly and disassembly of an air supply skirt and a bowl on the main body of a sprayer.

[0100] The variable volume chamber C100 of the magneto-pneumatic system 100 may, as a variant, be supplied with a pressurized gas other than air.

[0101] According to a variant of the invention not shown, the variable volume chamber C100 of the system 100 can be supplied with liquid, in particular water, to control the movement D of the piston 106. In this case, the system 100 is a magneto-hydraulic system.

[0102] According to another variant, during the sub-step of [Fig.4], the edge 642 of the sleeve 64 comes to bear against the support 110 and not against the magnet 112. This allows also to create a closed magnetic flux of the type of closed magnetic flux FM shown in [Fig.4].

[0103] The magneto-pneumatic system 100 can be used automatically, using the magnetic force generated by the permanent magnet 114 and controlling the supply of pressurized air into the variable volume chamber C100 or its evacuation by means of valves controlled by an electronic control unit not shown. Thus, the operation of the magneto-pneumatic system 100 during the assembly or disassembly of the subassembly 22 can be automated, which relieves an operator working near the sprayer 2 and makes his work less dangerous.

[0104] In a variant of the invention not shown, the O-rings 20 are mounted in grooves provided on the bottom 628a of the hollow housing 628 and / or grooves equivalent to the grooves 628c and 628d are provided on the front face 428 of the external part 42 of the main body 4.

[0105] In the second, third and fourth embodiments of the invention shown in Figures 7 to 9, elements similar to those of the first embodiment bear the same references. In the following, if a reference is used in the description without being shown in one of Figures 7 to 9 or if a reference is shown in one of these figures without being mentioned in the description, it relates to the same element as that bearing the same reference in the first embodiment.

[0106] In the second, third and fourth embodiments, no magneto-pneumatic or magneto-hydraulic system, of the type of system 100 of the first embodiment, is provided.

[0107] In the second embodiment, the permanent magnet 14 is mounted on the bowl 8, while an annular front surface 682 of the collar 649, which is made of ferromagnetic material, is arranged opposite the magnet 14 in the mounted configuration of a subassembly 22 defined as in the first embodiment. The magnet 14 and the surface 682 of the collar 649 constitute first and second magnetic coupling means between the parts 6 and 8.

[0108] The sleeve 64 of the air supply skirt 6 is provided, on its external radial surface 64, with a thread 650, while the external part 42 of the main body 4 is provided, in the housing L2, with a thread 421 complementary to the thread 650. Thus, once formed, the subassembly 22 can be screwed onto the main body 4 during the assembly of the air supply skirt 6 and the bowl 8 on the sprayer 2, using the thread 650 and the thread 421, until the rear edge of the sleeve is brought into contact with the bottom 423 of the housing L2 or the bottom 628a of the hollow housing 628 into contact with the front face 428.

[0109] Conversely, during disassembly, the subassembly 22 is removed by unscrewing it.

[0110] In the third embodiment, the permanent magnet 14 is positioned on the collar 649 as in the first embodiment. The surface 82 is formed by a ring 83 made of ferromagnetic material attached to the bowl 8 which is not necessarily made of ferromagnetic material and which is, for example, made of aluminum.

[0111] Here, the sleeve 64 of the air supply skirt 6 mainly comprises the collar 649, but no part which extends into the hollow housing 628. A skirt 651 which surrounds the hollow housing 628 is provided, on its internal radial surface, with a thread 653, while the external part 42 of the main body 4 is provided, on its external radial surface, with a thread 423. Thus, once formed, the subassembly 22 can be screwed onto the main body 4 when mounting the air supply skirt 6 and the bowl 8 on the sprayer 2, using the thread 423 and the thread 653, until the bottom 628a of the hollow housing 628 is brought into abutment against the front face 428.

[0112] Conversely, during disassembly, the subassembly 22 is removed by unscrewing it.

[0113] In the fourth embodiment, the surface 82 of the bowl 8 is in one piece with the rest of the bowl and the permanent magnet 14 is positioned on the collar 649 as in the first embodiment.

[0114] Here, a permanent magnet 441 is housed at the bottom of the housing L2 and cooperates with the rear edge 642 of the sleeve 64 to exert, on the subassembly 22 defined as in the first embodiment, a magnetic clamping force on the main body 4.

[0115] As a variant of this fourth embodiment, the magnet 441 can be mounted on the rear of the sleeve 64 and cooperate with the rotor which is then at least partly made of ferromagnetic material.

[0116] In the second, third and fourth embodiments, the assembly of the sprayer 2 takes place in two stages, as in the first embodiment. In a first assembly stage, the air supply skirt 6 and the bowl 8 are assembled and held together by the magnetic force between the magnet 14 and the surface 82 or 682, so as to constitute the subassembly 22. In a second assembly stage, the subassembly 22 is attached in one operation to the main body (4). During disassembly, in a first stage, the subassembly 22 is separated from the main body in one operation. Then, in a second disassembly stage, the air supply skirt 6 and the bowl 8 are separated from each other, against the magnetic force between the magnet 14 and the surface 82 or 682.

[0117] Alternatively and whatever the embodiment, sprayer 2 is of the electrostatic type with external charge and comprises a high-voltage unit and charging electrodes not shown, configured to bring the coating product sprayed by sprayer 2.

[0118] According to another variant applicable to all embodiments, the sprayer is not of the electrostatic type.

[0119] Alternatively, instead of a single annular permanent magnet 14, several permanent magnets distributed around the axis of rotation can be used as magnetic coupling means.

[0120] Alternatively, the surface 108 is not produced directly on the rotor 10 but on another rotating member, for example a hollow shaft driven by the rotor.

[0121] The invention is described above in the context of its use for spraying liquid coating product. It also applies to spraying powder coating product.

[0122] As far as technically possible, the embodiments and variants mentioned above can be combined.

Claims

Claims

1. Rotary sprayer for coating product (2) comprising a main body (4) and a bowl (8) driven in rotation by a rotating member (10), around an axis of rotation (A2) defined by the main body, the bowl being equipped with first magnetic coupling means (82; 14) capable of cooperating with second complementary magnetic coupling means (14; 682) fixed on a non-rotating part (6) of the sprayer for coating product (2), the first and second coupling means being capable of exerting a force (El) at least partially axial relative to the axis of rotation (A2) of the bowl (8), this force inducing the rotational coupling of the bowl (8) with the rotating member, characterized in that the second magnetic coupling means (14, 682) are carried by an air supply skirt (6) attached to the main body (4).

2. Sprayer according to claim 1, characterized in that the second magnetic coupling means (14; 682) are mounted on, or formed by, an internal collar (649) of the air supply skirt (6), bearing on a front face (428) of the main body (4).

3. Sprayer according to one of the preceding claims, characterized in that the first magnetic coupling means (82) are formed by a ferromagnetic part (82; 83) of the bowl and the second magnetic coupling means are formed by at least one permanent magnet (14).

4. Sprayer according to claim 1 or 2, characterized in that the first magnetic coupling means are formed by at least one permanent magnet (14) and the second magnetic coupling means are formed by a ferromagnetic part (682) of the air supply skirt (6).

5. Sprayer according to one of the preceding claims, characterized in that it comprises a magneto-pneumatic or magneto-hydraulic system (100) which includes - a magnetic device (100A) for attaching the air supply skirt (6) to the main body (4); and - a pneumatic or hydraulic mechanism (100B) for locking and tightening the air supply skirt to the main body.

6. Coating product sprayer according to claim 5, characterized in that the magnetic attachment device (100A) is configured to exert, between the air supply skirt (6) and the main body (4), an axial magnetic force, parallel to a longitudinal axis (A2) of the sprayer, with a first intensity (II), in that the pneumatic or hydraulic clamping mechanism (100B) is configured to exert between the air supply skirt and the main body an axial mechanical force, parallel to the longitudinal axis of the sprayer, with a second intensity (12) and in that the second intensity is strictly greater than the first intensity.

7. Coating product sprayer according to claim 6, characterized in that it comprises seals (20) arranged between the air supply skirt (6) and the main body (4) and in that the seals compressed by the mechanical force exerted by the pneumatic or hydraulic clamping mechanism (100B) isolate conforming air circulation ducts (422, 622) arranged in the main body (4) and in a body (62) of the air supply skirt (6), from the outside of the sprayer (2).

8. Coating product sprayer according to one of claims 1 to 4, characterized in that the air supply skirt (6) is provided with reliefs (650, 653) for screwing onto complementary reliefs (421, 423) provided on the main body (4).

9. Coating product sprayer according to one of claims 1 to 4, characterized in that the air supply skirt (6) is clamped to the main body by a magnetic force exerted between a part (441) of the main body (44) and a part (642) of the air supply skirt.

10. Method for mounting and / or dismounting a coating product sprayer according to one of the preceding claims, wherein - when mounting the sprayer, • in a first mounting step, the air supply skirt (6) and the bowl (8) are assembled and held together by a magnetic force between the first and second magnetic coupling means (14, 82; 14, 682); • in a second mounting step, a subassembly (22) formed of the air supply skirt (6) and the bowl (8) is attached in one operation to the main body (4); when dismantling the sprayer, in a first disassembly step, the subassembly (22) formed of the air supply skirt (6) and the bowl (8) is separated from the main body in one operation; and in a second disassembly step, the air supply skirt (6) and the bowl (8) are separated from each other, against the magnetic force between the first and second magnetic coupling means (14, 82; 14, 682).

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