Rotary atomizer

Abstract

A rotary atomizer spindle arrangement comprising a rotary atomizer spindle having a shaft member (1a) journalled for rotation in a body of the rotary atomizer spindle and comprising a bell cup (2) releasably mounted to the shaft member (1a). The bell cup (2) has a bell portion (21) for spraying a medium during rotation and a mounting portion (22) mounting the bell cup to the shaft member (1a). The shaft member and the bell cup mounting portion each comprise complementary cone portions (11, 23) which form an interference fit with each other when the bell cup is mounted to the shaft member, thereby positioning the bell cup relative to the shaft member. The rotary atomizer spindle arrangement comprises a bell cup retaining arrangement (5, 24) having biasing retaining means for facilitating the complementary cone portions (11, 23) abutting against each other when the bell cup (2) and the shaft member (1a) are in a first relative rotational position relative to each other, while the bell cup retaining arrangement (5, 24) allows at least the bell cup (2) to be removed from the shaft member (1a) when the bell cup (2) and the shaft member (1a) are in a second relative rotational position relative to each other.

Description

[0001] This invention relates to a rotary atomizer, a rotary atomizer spindle, and a rotary atomizer bell cup.

[0002] Rotary atomizers can be used for surface coating in a variety of situations. One specific application of rotary atomizers is in the field of pigment spraying. For example, in the automotive industry, such rotary atomizers are commonly used for painting vehicles. In some cases, the spindle of the rotary atomizer is mounted on a robotic arm, and the atomizer is moved in space to different orientations for painting the vehicle. In other cases, different support arrangements can be provided.

[0003] More commonly, rotary atomizers are used as paint coaters in high-volume production environments. Also known as "spray bells" or "bell coaters," they are used for high-volume painting due to their superior transfer efficiency, pattern consistency, and low compressed air consumption compared to spray guns.

[0004] The bell-shaped cup comprises a conical or arcuate disc fixed to a shaft of a drive spindle, which may be driven, for example, by a turbine. Paint is injected into the center of the rear of the disc, and centrifugal force forces the paint out of the edge of the cup, thus atomizing it. The paint flows through the cup and away from the edge, dispersing it into atomized droplets. In use, the turbine is a high-speed, high-precision air motor that rotates the bell-shaped cup at speeds ranging from 10,000 rpm to 100,000 rpm, depending on the cup diameter, the desired degree of atomization, and the physical properties of the paint. This typical turbine used in the application employs air bearings, with the rotating shaft suspended on a buffer formed by compressed air, thus generating almost no frictional resistance.

[0005] An electrostatic system is typically provided to ensure effective coating of the workpiece. This system can be internal or external (or directly or indirectly charged) and is arranged to supply a high voltage (e.g., 30,000 to 100,000 V DC) charge to the coater or the air around it. This has the effect of negatively charging the coating while simultaneously creating a positively charged region on the workpiece, resulting in an electrostatic attraction between the coating and the workpiece.

[0006] In various environments, such as automotive painting, production line reliability and minimizing downtime are crucial. Typically, bell cups need to be cleaned periodically and sometimes replaced. Usually, this requires stopping the paint booth production line to allow maintenance personnel to perform cleaning and / or bell cup replacement. Even with automated systems, downtime often occurs during cleaning and / or replacement.

[0007] Traditional clock-shaped cups are fixed to the drive shaft with screws.

[0008] The small pitch of the bolts used to secure the bell cups leads to longer disassembly and replacement times. Furthermore, manufacturing issues may arise due to potential mechanical misalignment between the bell cup / shaft threads and the locating cones within these components, potentially causing excessive runout and resulting in vibration at speed. Additionally, the threads of the bell cups are prone to damage / crossing, especially when made of relatively soft materials such as aluminum.

[0009] To address this issue, magnetic snap-fit ​​systems have been proposed, using a number of magnets to secure the bell cup to the shaft. However, this system has been found to have significant problems. Given that the bell cup can rotate at very high speeds, there is a risk that the cup may not be adequately secured to the shaft, failing to withstand the high-speed rotation. This could potentially lead to atomizer failure or even cause the bell cup to fly out of the atomizer and damage surrounding objects such as the spray booth or the vehicle being painted.

[0010] Furthermore, it has been found that magnets installed in such systems can crack or fail over time, especially when they are operated intentionally or unintentionally at speeds exceeding their design operating speed.

[0011] Furthermore, providing such magnets is undesirable because it would often necessitate the use of heavy and expensive permanent magnet components in the rotating parts of the system (i.e., the shafts and / or the bell cup). Adding any mass to the rotating parts of the system that is not strictly necessary is also undesirable. This could lead to increased manufacturing costs and / or increased speed constraints.

[0012] Therefore, it is desirable to develop a rotary atomizer spindle and bell cup that can be used in the system to alleviate at least some of the aforementioned problems.

[0013] According to a first aspect of the invention, a rotary atomizer spindle arrangement is provided, comprising a rotary atomizer spindle having a shaft member supported by a journal within a body of the rotary atomizer spindle for rotation, and including a bell cup releasably mounted to the shaft member, the bell cup having a bell-shaped portion and a mounting portion, the bell-shaped portion for spraying a medium during rotation, the mounting portion mounting the bell cup to the shaft member, the shaft member and the mounting portion of the bell cup each including complementary conical portions, the conical portions forming with each other when the bell cup is mounted to the shaft member. An interference fit is provided to position the bell cup relative to the shaft, wherein the rotary atomizer spindle arrangement includes a bell cup retaining arrangement with an offset retaining device, the bell cup retaining arrangement facilitating abutment of the complementary cone portions relative to each other when the bell cup and the shaft are in a first relative rotational position relative to each other, while the bell cup retaining arrangement allows at least removal of the bell cup from the shaft when the bell cup and the shaft are in a second relative rotational position relative to each other, and the bell cup retaining arrangement includes a locking device for locking the bell cup and the shaft in the first relative rotational position.

[0014] This can result in an arrangement in which complementary cone portions position the bell cup relative to the shaft as desired (e.g., to promote concentricity between the shaft and the bell cup), while the retaining arrangement facilitates effective retention of the carried bell cup and allows for rapid release of the bell cup when desired for removal. An offset retaining device ensures effective contact between the cones for easy alignment, and a locking device prevents accidental removal of the bell cup.

[0015] Typically and preferably, when the bell cup and the shaft are in a second relative rotational position relative to each other, the bell cup retaining arrangement will allow for the installation and removal of the bell cup from the shaft. However, it is conceivable that a bell cup retaining arrangement can be provided that allows the bell cup to be installed on the shaft when the bell cup and the shaft are in a third relative rotational position relative to each other, and that does not allow the bell cup to be installed on the shaft when the bell cup and the shaft are in a second relative rotational position relative to each other.

[0016] The bell-cup retaining arrangement may include a retaining assembly carried on one of the shaft and the bell-cup, and includes a bias retaining device and a sleeve having at least one first engaging portion, which, under the action of the bias retaining device, acts on the other of the shaft and the bell-cup, thereby causing the complementary cone portions to abut against each other.

[0017] Therefore, it can be noted that in this case, the sleeve is biased in the holding direction of the bell cup.

[0018] The sleeve can be held to resist rotation relative to one of the shaft and the bell cup carrying the retaining assembly.

[0019] The complementary conical portions are arranged such that the shaft has an inner conical portion and the bell cup has an outer conical portion. While not the most preferred arrangement, the complementary conical portions can be arranged such that the shaft has an outer conical portion and the bell cup has an inner conical portion. It is foreseeable that the latter arrangement will generally result in an increase in rotational mass.

[0020] The bell-shaped cup retaining arrangement may include at least one complementary engaging retaining portion disposed on the other of the shaft and the bell-shaped cup, for engaging with at least one first engaging portion under the action of the bias retaining device.

[0021] Preferably, the retaining assembly is carried on a shaft. Preferably, the bell-shaped cup is provided with at least one complementary engaging retaining portion.

[0022] At the location where the retaining assembly is supported within the shaft, the shaft may include a plurality of internal locating protrusions for limiting axial movement of the sleeve relative to the shaft. The internal locating protrusions can retain the sleeve against rotation relative to the shaft.

[0023] In one set of embodiments, at least one first engaging portion includes a recess in the sleeve, and at least one complementary engaging retaining portion includes a protrusion.

[0024] Preferably, the sleeve includes a plurality of first engaging portions, and a plurality of corresponding complementary engaging retaining portions are provided on the other of the shaft and the bell cup.

[0025] The first engaging portion, or each first engaging portion, may be disposed on an axially facing surface of the sleeve. The sleeve may include an annular portion having an axially facing irregular surface that defines the first engaging portion, or each first engaging portion. The annular portion may include, for example, an axial end of the sleeve or a flange disposed on the sleeve.

[0026] The retaining component can be disposed in a ring belt, which is defined between the shaft and the mounting portion of the bell cup.

[0027] A sleeve may be disposed in a ring band that is defined between the shaft and the mounting portion of the bell cup.

[0028] The bias holding device may be disposed in a ring band defined between the shaft and the mounting portion of the bell cup.

[0029] The bias holding device may include at least one spring, such as a metal spring. The bias holding device may include a spring assembly comprising multiple springs. The bias holding device may include a portion of an elastic material, such as a portion of a plastic material, for example, including one or more O-coils.

[0030] The retaining assembly may include a biasing device support portion that provides a support surface against the action of the biasing retaining device when the complementary convex portions are abutted against each other. The biasing device support portion may include a spring seat having a spring support surface that resists the action of at least one spring.

[0031] The biasing device support portion may be ring-shaped and arranged to be mounted to one of the shaft and bell cup of the bearing retaining assembly.

[0032] The biasing device support portion may be disposed in a ring band, which is defined between the shaft and the mounting portion of the bell cup.

[0033] The locking device may include a locking member and a locking biasing device for biasing the locking member toward a locked position.

[0034] The locking member may have at least one stop portion for engaging with a corresponding complementary locking engagement portion when the locking member is in the locked position to prevent the shaft and the bell cup from rotating away from the first relative rotational position.

[0035] In one set of embodiments, at least one stop portion includes a recess, and at least one complementary locking engagement portion includes a protrusion.

[0036] The locking component may include a sleeve. A stop portion may be provided on the sleeve, and a complementary locking engagement portion may be provided on the other of the shaft and the bell cup.

[0037] The stop portion, or each stop portion, may be disposed on an axially oriented surface of the sleeve. The sleeve may include an annular portion with an axially oriented irregular surface that defines the stop portion, or each stop portion.

[0038] The first engaging portion or each first engaging portion and the stop portion or each stop portion may be disposed on an axially oriented surface of the sleeve. The sleeve may include an annular portion with an axially oriented irregular surface that defines the first engaging portion or each first engaging portion and the stop portion or each stop portion.

[0039] A common bias device can be set up, which can also serve as a locking bias device and a bias holding device.

[0040] This simplifies manufacturing and minimizes the mass of the rotating system.

[0041] At least one stop portion and at least one first engagement portion can both be provided by the corresponding common portion of the sleeve.

[0042] The common portion of the sleeve may include a recess. In this case, if there are multiple stop portions and first engagement portions, there will be multiple corresponding recesses.

[0043] At least one complementary engagement retaining portion and at least one complementary locking engagement portion can be provided by a corresponding common portion of the shaft and the other of the bell cup.

[0044] The common portion of the other of the shaft and bell cup may include a protrusion. In this case, if there are multiple complementary engaging and retaining portions and complementary locking and engaging portions, there will be multiple corresponding protrusions.

[0045] The arrangement can be configured as a bayonet-style installation.

[0046] The sleeve may include a cam surface leading to at least one stop portion, such that when the bell cup rotates relative to the shaft toward or away from a first relative rotational position, complementary locking engagement portions ride on the cam surface toward or away from the stop portion. The cam surface may include the axially oriented profiled surface.

[0047] The stop portion and cam surface can be arranged to allow relative rotation of the bell cup and shaft from the second rotational position to the first relative rotational position and from the first relative rotational position to the second rotational position under the action of external torque, but to resist rotation from the first relative rotational position to the second rotational position in the absence of such torque. This external force can be provided by the user or by an actuator system such as a robot.

[0048] Typically, at the retaining arrangement, and at the positions of the stop and the cam surface, the arrangement can be configured to resist relative rotation between the bell cup and the shaft, opposite to the requirement of movement to the second relative rotational position. This means that relative rotation that may occur between the bell cup and the shaft due to rotational drive can be resisted. If a clockwise rotation of the bell cup relative to the shaft is required for movement from the first relative rotational position to the second rotational position, then the retaining arrangement would be configured to retain the bell cup against counterclockwise rotation relative to the shaft, while the bell cup would be driven clockwise in the direction in which the drive acts in the direction in which the relative rotation is resisted, which is practically impossible.

[0049] The sleeve can be arranged to move axially relative to the shaft and the bell cup, and to resist the action of the biasing device when the bell cup is installed onto and / or removed from the shaft.

[0050] This helps to ensure full contact between the complementary cone portions during installation and removal, particularly during locking and unlocking of the bell cup, thus guaranteeing this close contact when the bell cup is installed onto the shaft. In this case, as the locking engagement portion rides on the cam surface, (“backwards”) the sleeve is forced to resist the action of the biasing device.

[0051] It should be noted that the biasing device in the current system can both hold the bell cup and operate the latch. This is in contrast to typical bayonet mounts (such as light bulbs), in which the biasing device affecting the locking would drive the retainer (light bulb) away from its bracket (lamp holder).

[0052] The sleeve may have an inner hole.

[0053] The inner bore can be used to accept the mounting portion of a bell cup or shaft.

[0054] The inner bore can be used to allow at least one material delivery tube to pass through, thereby delivering the material to be sprayed to the bell cup.

[0055] The sleeve may include at least one groove arranged to allow passage of a protrusion, which serves as a complementary engagement retaining portion and a complementary locking engagement portion, from a first end of the sleeve to a second end of the sleeve.

[0056] This facilitates the insertion of the sleeve into the mounting portion of the shaft or bell cup.

[0057] The at least one groove may be provided on the surface defining the inner hole.

[0058] The at least one groove may be a straight groove and may be parallel to the axis of the sleeve.

[0059] The outlet of the at least one internal groove can lead to the axially oriented irregular surface of the sleeve.

[0060] In one set of embodiments, the retaining assembly is carried on the shaft, the sleeve includes at least one recess that serves as both a stop and a first engagement portion, and the bell cup includes at least one protrusion that serves as both a complementary engagement retaining portion and a complementary locking engagement portion, and the protrusion engages with the recess when the bell cup and the shaft are in a first relative rotational position.

[0061] According to another aspect of the invention, a rotary atomizer is provided, comprising a rotary atomizer spindle arrangement as defined above and a material supply arrangement for supplying the material to be sprayed.

[0062] The spindle arrangement of the rotary atomizer may include a sleeve as defined above, and the material supply arrangement may include at least one material supply tube through a hole in the sleeve.

[0063] According to another aspect of the invention, a rotary atomizer spindle is provided, which is arranged for use as part of a rotary atomizer spindle arrangement as defined above.

[0064] According to another aspect of the invention, a rotary atomizer shaft is provided, which is arranged for use as part of a rotary atomizer spindle arrangement as defined above.

[0065] According to another aspect of the invention, a rotary atomizer spindle with a shaft journal supported in the body of the rotary atomizer spindle for rotation is provided and arranged to receive a bell cup having a bell-shaped portion for spraying a medium during rotation. The shaft includes a conical portion that, when the bell cup is mounted onto the shaft, is used to receive a complementary conical portion of the bell cup to position the bell cup relative to the shaft. The rotary atomizer spindle includes a bell cup holding assembly having an offset holding device that, when the bell cup and the shaft are in a first relative rotational position relative to each other, facilitates abutment of the complementary conical portions against each other, and when the bell cup and the shaft are in a second relative rotational position relative to each other, allows at least the bell cup to be removed from the shaft. The bell cup holding assembly includes a locking device for locking the bell cup and the shaft in the first relative rotational position.

[0066] According to another aspect of the invention, a rotary atomizer shaft arrangement is provided, the shaft being arranged such that it is journal-supported in the body of the rotary atomizer spindle for rotation, and is arranged to receive a bell cup having a bell-shaped portion for spraying a medium during rotation, the shaft including a conical portion for receiving a complementary conical portion of the bell cup when the bell cup is mounted onto the shaft, so as to position the bell cup relative to the shaft, wherein the rotary atomizer shaft arrangement further includes a bell cup retaining assembly mounted on the shaft and having an offset retaining device, the bell cup retaining assembly for causing the complementary conical portions to abut against each other when the bell cup and the shaft are in a first relative rotational position relative to each other, and the bell cup retaining assembly for at least allowing the bell cup to be removed from the shaft when the bell cup and the shaft are in a second relative rotational position relative to each other, and the bell cup retaining assembly including a locking device for locking the bell cup and the shaft in the first relative rotational position.

[0067] The retaining assembly may include a sleeve having at least one first engaging portion for acting on the carried bell cup under the action of the bias retaining device, thereby causing complementary vertebral portions to abut against each other.

[0068] According to another aspect of the invention, a rotary atomizer shaft arrangement is provided, the shaft being arranged such that its journal is supported within the body of the rotary atomizer spindle for rotation, and is arranged to receive a bell-shaped cup having a bell-shaped portion for spraying a medium during rotation, the shaft including a conical portion that, when the bell-shaped cup is mounted onto the shaft, serves to receive a complementary conical portion of the bell-shaped cup to position the bell-shaped cup relative to the shaft, wherein the rotation... The atomizer shaft arrangement further includes a bell cup retaining assembly mounted on the shaft. The retaining assembly includes an offset retaining device and a sleeve having at least one stop portion. The sleeve is used to receive a retaining lug disposed on the carried bell cup and to retain the carried bell cup against rotation relative to the shaft. The offset retaining device acts on the sleeve to pull the sleeve into the shaft such that the retaining lug of the carried bell cup is held in the stop portion and the carried bell cup is propelled into the shaft.

[0069] According to another aspect of the invention, a rotating bell cup is provided, which is arranged for use as part of the rotating atomizer spindle arrangement defined above.

[0070] According to another aspect of the invention, a rotary atomizer bell cup is provided, which is mounted to a shaft of a rotary atomizer spindle as defined above, and has a bell-shaped portion and a mounting portion, the bell-shaped portion for spraying a medium during rotation, the mounting portion for mounting the bell cup on the shaft, and further includes a conical portion for forming an interference fit with a complementary conical portion on the spindle, wherein the bell cup further includes at least one protrusion arranged as a complementary engagement retaining portion and a complementary locking engagement portion.

[0071] Please note that, generally speaking, and with any necessary modifications to the wording, all additional features according to any aspect of the invention as defined above can be applied as additional features of all other aspects of the invention as defined above. For the sake of brevity, these additional features are not repeated after each aspect of the invention.

[0072] Embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which:

[0073] Figure 1 A rotary atomizer in the form of a paint sprayer is schematically shown;

[0074] Figure 2 schematically shown separately Figure 1 The rotary atomizer shown is arranged along its spindle.

[0075] Figure 3 The illustration shows, separately, the items included. Figure 1 The rotary atomizer shown Figure 2 The bell-shaped cup in the spindle arrangement of the rotary atomizer shown;

[0076] Figure 4 yes Figure 2 The cross-sectional view of a portion of the spindle arrangement of the rotary atomizer shown reveals internal details, including details of the bell cup retaining arrangement.

[0077] Figure 5A and Figure 5B A perspective view of the sleeve is shown, which constitutes... Figure 4 Part of the fixed arrangement of the bell-shaped cups shown; and

[0078] Figure 6 A spring seat is shown, which constitutes a Figure 4 Part of the fixed arrangement of the bell-shaped cups shown.

[0079] Figure 1A rotary atomizer in the form of a paint spraying machine is schematically shown, comprising a rotary atomizer spindle 1 and a paint spraying bell cup 2, which together are considered a rotary atomizer spindle arrangement. The rotary atomizer spindle 1 is arranged to rotatably drive the paint spraying bell cup 2. The spindle 1 includes a shaft 1a, which is supported by a journal in at least one air bearing (not shown), and carries a turbine impeller 1b (in... Figure 2 As can be seen in the image, the turbine impeller is used to rotate the drive shaft 1a under the action of the driving gas.

[0080] Figure 1 The paint spraying machine shown also includes a supply arrangement 3 for supplying material (i.e., paint in this case) from a storage tank 4 to a bell cup 2, such that the paint is atomized by the bell cup 2 and projected onto the surface to be coated. Typically, for this type of paint spraying machine, the paint is projected onto the surface to be painted by electrostatic force generated by a high voltage applied between the spindle 1 and the surface to be painted.

[0081] It should be noted that alternatives to turbine drives can be used, such as electrically driven shafts.

[0082] At this level, the structure and operation of paint spraying machines are conventional, and such machines are widely used and well understood in the art. Of particular interest in this application are the features of the rotary atomizer spindle arrangement, especially the features of the mounting arrangement of the bell-shaped cup 2 on the rotary atomizer spindle 1. Reference will be made below specifically to... Figures 2 to 6 To describe these features in detail.

[0083] The bell-shaped cup 2 is a replaceable component, arranged to be releasably mounted to the rotary atomizer spindle 1, specifically to shaft 1a. Figure 3 A separate bell-shaped cup 2 can be seen in the middle. Figure 1 , Figure 2 and Figure 4 As can be seen, the bell-shaped cup 2 is mounted on the shaft 1a.

[0084] The bell-shaped cup 2 includes a bell-shaped portion 21 for spraying a medium during rotation and a mounting portion 22 for mounting the bell-shaped cup 2 to the shaft 1a. The mounting portion 22 includes a conical portion 23, that is, a partially conical surface, which is arranged to mate with a corresponding complementary conical portion 11 disposed at the end of the shaft 1a, that is, to form an interference fit (see [link to documentation]). Figure 4 ).

[0085] In this embodiment, the vertebral portion 23 on the bell-shaped cup 2 is the outer vertebral body, and the vertebral body in the shaft 11 is the inner vertebral body. However, in an alternative, these two can be interchanged, such that the shaft 1a has the outer vertebral body, while the bell-shaped cup 2 has the inner vertebral body. However, it is foreseeable that this arrangement will result in an increased mass in the rotating system, and therefore may not be the most preferred option in most cases.

[0086] The bell-shaped cup 2 also includes multiple, in this embodiment four, retaining lugs 24. In this embodiment, these retaining lugs 24 are positioned at the distal end of the mounting portion 22. The retaining lugs 24 form part of the retaining arrangement, which will be described in detail below.

[0087] In this embodiment, shaft 1a houses retaining assembly 5. This retaining assembly 5 is arranged to interact with retaining lug 24, and the retaining assembly 5 and retaining lug 24 together can be considered to form a bell-shaped cup retaining arrangement.

[0088] The retaining assembly 5 is disposed in the main bore of the shaft 1a, and when the bell cup 2 is mounted in the shaft 1a, the main portion of the mounting portion 22 of the bell cup 2 extends through the retaining assembly 5. Therefore, the retaining assembly is disposed in an annular band defined between the shaft 1a and the bell cup 2. This arrangement ensures that the internal main bore 25 of the bell cup 2 extending through the mounting portion 22 is unobstructed, thereby allowing one or more feed tubes (not shown) forming part of the supply arrangement 3 to pass through the rotary atomizer spindle 1 and the bell cup 2, thereby supplying the material to be sprayed to the bell cup 2.

[0089] The bell-shaped cup fixing assembly includes a sleeve 6, a biasing device (in this embodiment, the biasing device is in the form of a spring assembly 7), and a spring seat portion 8.

[0090] Multiple (four in this embodiment, two of which can be disposed in shaft 1a) are provided in the shaft member 1a. Figure 4 As can be seen from the image, retaining bolts 9, which, as inwardly projecting portions, control the possible range of axial movement of the sleeve 6 and maintain the sleeve 6 against rotational movement within the shaft 1a. Each end of each retaining bolt 9 is received in a respective groove 61 provided in the sleeve 6. By considering... Figure 4 and Figure 5B It can be seen how these retaining bolts 9 prevent relative rotation between the shaft 1a and the sleeve 6, while allowing the sleeve 6 a certain range of axial movement. The bolts 9 interact with the sidewalls of the groove 61, thus maintaining resistance to rotation, while the bolts 9 interact with the closed end of the groove 61, thus limiting the axial travel.

[0091] The biasing device (i.e., spring assembly 7 in this embodiment) is housed between the flange 62 provided on the sleeve 6 and the biasing device (or spring) support surface 81 provided on the spring seat 8. Figure 6 As can be seen from the image, the spring support 8 is an annular component. The spring seat 8 has an external threaded portion 82, which is arranged to be received in a complementary threaded portion at the end of the shaft 1a.

[0092] Therefore, with the bolt 9 in place in the assembly, the sleeve 6 can be introduced into the end of the shaft 1a first, and then the spring assembly 7 can be positioned around the sleeve 6, that is, in the annulus formed between the sleeve 6 and the inner wall of the shaft 1a. Then the spring seat 8 is screwed in so that the spring assembly 7 is captured between the spring seat 8 and the sleeve 6, so that the spring assembly acts between the flange 62 of the sleeve 6 and the biasing device support surface 81.

[0093] In this assembled state, when the end of the groove 61 meets the retaining screw 9, the axial movement of the sleeve 6 in the first direction stops, and the axial movement in the opposite direction is countered by the biasing device (i.e., the spring assembly 7). However, as long as the force of the biasing device 7 can be overcome, the sleeve 6 can be moved axially within a certain range.

[0094] from Figure 5A and Figure 5B As can be seen optimally, the sleeve 6 also includes a plurality of (four in this embodiment) internal grooves 63, which are disposed on the wall defining the hole of the sleeve 6. In this embodiment, the internal grooves 63 are generally straight grooves and are parallel to the axis of the sleeve 6. When the bell cup 2 is mounted on the shaft 1a, the grooves 63 are arranged to receive retaining lugs 24 disposed on the bell cup 2. During this mounting, the retaining lugs 24 travel along their respective grooves 63. When the bell cup 2 is fully inserted along this path, each retaining lug 24 reaches its respective exit point 63a of the groove 63 along the path it has traveled (see See...). Figure 5A The sleeve 64 enters from the exit point 63a onto the axially oriented irregular end surface 64. In this embodiment, there are four such exit portions 63a (one for each groove 63), and the irregular axially oriented surface of the sleeve 64 includes a plurality of (four in this embodiment) cam surfaces 64a, each cam surface leading from the respective exit point 63a of the groove 63 to a respective stop portion 64b. In this embodiment, there are four stop portions 64b. The cam surfaces 64a are arranged such that, when rotated, each retaining lug 64 can ride on the cam surface 64a and enter the respective stop portion 64b. Further rotational travel of each lug 24 in the stated direction is prevented by a respective shoulder portion 64c.

[0095] This arrangement allows the bell cup 2 to rotate relative to the sleeve 6 and the shaft 1a, thus enabling the bell cup 2 to be torsionally locked into place. In this embodiment, approximately 1 / 8 turn is required for the retaining lug 24 to move from the outlet 63a of the respective recess 63 to the respective stop portion 64b. When this torsion occurs, the bell cup 2 will tend to be pulled further into the shaft 1a, reaching a point where the complementary conical portions 23 and 11 are in close contact with each other. Beyond this point, as the retaining lug 24 rides on the cam surface 64a and enters the respective stop portions 64b, further rotation of the bell cup 2 relative to the shaft 1 will tend to drive the sleeve 6 backward against the action of the biasing device 7.

[0096] Once this rotation occurs, and once the retaining lug 24b is positioned within the stop portion 64b, the biasing device (i.e., the spring assembly 7) tends to pull the bell cup 2 into the shaft 1a and applies a load to the mutually abutting complementary conical portions 23 and 11. Thus, the correct position of the bell cup 2 (e.g., a position of good concentricity between the bell cup 2 and the shaft 1a) can be achieved through the interaction of the cones 23 and 11, while the retention of the bell cup 2 is ensured by the retaining arrangement (i.e., the retaining assembly 5 and the retaining lug 24). The load acting on the bell cup 2 can be controlled by appropriately selecting the biasing device (e.g., selecting the spring strength).

[0097] Shaft 1a and bell cup 2 are also locked in this relative rotational position by sleeve 6 and biasing device (spring assembly 7).

[0098] Furthermore, when the rotational driving force is transmitted between the shaft 1a and the bell cup 2 during operation, this rotational load can be transmitted from the shaft 1a to the bell cup 2 by the frictional force at the interference fit between the complementary cones 23 and 11, and by the action of the shoulder 64c associated with each stop portion 64b on the respective retaining lugs 24.

[0099] It should be noted that the sleeve 6 and the biasing device (spring assembly 7) serve as both part of the retaining system (i.e., the system that biases the bell cup 2 into the shaft 1a) and the locking device, with the sleeve 6 acting as the locking member. The retaining lug 24 serves as both the locking engagement portion and the engagement retaining portion.

[0100] When removing the bell cup 2 from the shaft 1a, a significant (but manually applicable) rotational force is required to rotate the bell cup 2 in the opposite direction to its installation direction, thereby overcoming the force of the biasing device. At this stage, as the lug 24 disengages from the stop portion 64b and runs on the cam surface 64a, the rotation of the bell cup 2 and the corresponding rotation of the retaining lug 24 drive the sleeve 6 backward against the biasing device, i.e., the spring assembly 7. From there, the lug 24 can re-enter the groove 63 of the sleeve 6, allowing the bell cup 2 to be removed from the shaft 1a.

[0101] When installing and removing the bell cup 2, the shaft 1a can be held in several different ways if desired. For example, the shaft 1a can be provided with two axial planes (not shown) that can be held by means of a wrench, or as another embodiment, a shaft locking mechanism (not shown) can engage with the shaft 1a.

[0102] While the arrangement of carrying the bell-shaped cup retaining assembly in the shaft 1a, as described above, is preferred, it is conceivable that the situation could be reversed, with the bell-shaped cup 2 carrying the bell-shaped cup retaining assembly, and appropriate retaining lugs provided on the shaft 1a. In most cases, this is not optimal, as it would tend to increase the complexity and cost of each bell-shaped cup 2, which would need to be replaced periodically.

Claims

1. A rotary atomizer spindle arrangement comprising a rotary atomizer spindle having a shaft and a bell cup releasably mounted to the shaft, the shaft being supported by a journal within the body of the rotary atomizer spindle for rotation, the bell cup having a bell-shaped portion and a mounting portion, the bell-shaped portion for spraying a medium during rotation, the mounting portion mounting the bell cup to the shaft, the shaft and the mounting portion of the bell cup each comprising a complementary conical portion, the conical portions forming an interference fit when the bell cup is mounted to the shaft, thereby... The bell cup is positioned relative to the shaft, wherein the rotary atomizer spindle arrangement includes a bell cup holding arrangement with an offset holding device, the bell cup holding arrangement facilitating the abutment of the complementary conical portions against each other when the bell cup and the shaft are in a first relative rotational position relative to each other, while the bell cup holding arrangement allows at least the removal of the bell cup from the shaft when the bell cup and the shaft are in a second relative rotational position relative to each other, and the bell cup holding arrangement includes a locking device for locking the bell cup and the shaft in the first relative rotational position; The bell-shaped cup retaining arrangement includes a retaining assembly supported on one of the shaft and the bell-shaped cup. The retaining assembly includes a bias retaining device and a sleeve having at least one first engaging portion, which, under the action of the bias retaining device, acts on the other of the shaft and the bell-shaped cup, thereby causing the complementary conical portions to abut against each other. The sleeve has an axially oriented irregular end surface; The locking device includes the sleeve as a locking member and a locking biasing device for biasing the locking member toward a locked position; wherein the locking member has at least one stop portion disposed on the irregular end surface of the sleeve, the stop portion being configured to engage with a corresponding complementary locking engagement portion disposed on the other of the shaft and bell cup when the locking member is in the locked position, thereby preventing relative rotation of the shaft and bell cup away from the first relative rotational position; and The irregular end surface of the sleeve includes a cam surface leading to the at least one stop portion, such that when the bell cup rotates relative to the shaft toward or away from the first relative rotational position, the complementary locking engagement portion rides on the cam surface toward or away from the stop portion.

2. The rotary atomizer spindle arrangement according to claim 1, wherein the sleeve is arranged to move axially relative to the shaft and the bell cup, and resists the action of the bias holding device when the bell cup is installed onto and / or removed from the shaft.

3. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the sleeve is held to resist rotation relative to one of the shaft and the bell cup carrying the retaining assembly.

4. The rotary atomizer spindle arrangement of claim 3, wherein the retaining assembly is carried in the shaft, and the shaft includes a plurality of internal positioning protrusions for restricting axial movement of the sleeve relative to the shaft and maintaining resistance to rotation of the sleeve relative to the shaft.

5. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the bell cup retaining arrangement includes at least one complementary engaging retaining portion disposed on the other of the shaft and the bell cup for engaging with at least one first engaging portion under the action of the bias retaining device.

6. The rotary atomizer spindle arrangement according to claim 5, wherein the retaining assembly is carried on the shaft and the at least one complementary engaging retaining portion is disposed on the bell cup.

7. The rotary atomizer spindle arrangement of claim 5, wherein the at least one first engagement portion includes a recess in the sleeve, and the at least one complementary engagement retaining portion includes a protrusion.

8. The rotary atomizer spindle arrangement according to claim 5, wherein the sleeve includes a plurality of first engaging portions, and a plurality of corresponding complementary engaging retaining portions are provided on the other of the shaft and the bell cup.

9. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the first engaging portion or each first engaging portion is disposed on the axially facing surface of the sleeve.

10. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the retaining assembly is disposed in a ring band defined between the shaft and the mounting portion of the bell cup.

11. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the at least one stop portion includes a recess, and the corresponding complementary locking engagement portion includes a protrusion.

12. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the at least one stop portion and the at least one first engagement portion are both provided by corresponding common portions of the sleeve.

13. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the stop portion and cam surface are arranged to allow the bell cup and shaft to rotate from the second relative rotational position toward the first relative rotational position and from the first relative rotational position toward the second relative rotational position under the action of external torque, but to resist rotation from the first relative rotational position toward the second relative rotational position in the absence of such torque.

14. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein a common biasing device is configured to serve simultaneously as a locking biasing device and a bias holding device.

15. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the retaining arrangement is configured to maintain the bell cup and shaft against relative rotation, which is contrary to the relative rotation requirement of movement from the first relative rotation position toward the second relative rotation position.

16. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the sleeve includes at least one groove arranged to allow passage of a protrusion as at least one of a complementary engagement retaining portion and a complementary locking engagement portion from a first end of the sleeve to a second end of the sleeve.

17. The rotary atomizer spindle arrangement according to claim 1 or 2, wherein the retaining assembly is carried on the shaft, the sleeve includes at least one recess that serves as both a stop portion and a first engagement portion, and the bell cup includes at least one protrusion that serves as both a complementary engagement retaining portion and a complementary locking engagement portion, and the protrusion engages with the recess when the bell cup and the shaft are in the first relative rotational position.

18. A rotary atomizer, comprising: The rotary atomizer spindle arrangement and the material supply arrangement for supplying the material to be sprayed, according to any one of claims 1-17.

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