Centering unit with anti-rotation assembly

Abstract

The invention relates to a centering unit (10) comprising: a housing (11) in which a centering rod (13) is at least partially housed, the centering rod being linearly movable along an actuation axis (A) between a first minimum pull-out position pulled out of the housing (11) and a second maximum pull-out position pulled out of the housing (11); and an anti-rotation assembly (40) configured to prevent rotation of the centering rod (13) about the actuation axis (A) during movement of the centering rod between the first position and the second position; characterized in that the anti-rotation assembly (40) comprises a sliding block (41) fixedly connected to the centering rod (13) and a guide (42) fixedly connected to the housing (11), in which the sliding block (41) is constrained to slide along the guide (42) in a direction parallel to the actuation axis (A) by the intervention of at least one pair of rollers (46) arranged side by side, their respective roller shafts are contained in planes parallel to each other and are transverse to each other.

Description

Technical Field

[0001] This invention generally relates to centering units with anti-rotation components. In particular, this invention relates to centering units commonly used in sheet metal processing, such as those used in the manufacture of motor vehicle bodies. Background Technology

[0002] In the manufacture of motor vehicle bodies, it is well known that centering units are used, for example, to create special references to ensure the correct positioning of sheet metal on machining equipment.

[0003] For this purpose, known centering units are configured to allow the centering rod to move linearly along the actuation axis between two end positions: a first rest position where the centering rod is substantially retracted into the body of the centering unit, and a second operating position where the centering rod protrudes more from the body of the centering unit. The centering unit is typically controlled by a pneumatic or electric actuator that acts on an element axially movable between the two end positions, and through this element, the actuator acts on the centering rod to move it between the rest and operating positions.

[0004] To achieve a precise positional reference when the centering rod is in the operating position, the centering rod can, for example, have an asymmetrical shape at its free end, thus creating an abutment surface. In this configuration, it is important that the centering rod reaches the operating position without any rotation about the actuation axis. Otherwise, the abutment surface will provide an inaccurate reference for the desired positioning.

[0005] Known centering elements implement various solutions to maintain the angular position of the centering rod.

[0006] Document EP 1132628 describes the use of a connecting pin between the actuator piston and the centering rod. The pin extends off-axis parallel to the actuation axis.

[0007] Document US 8 366 085 describes the use of a pair of rollers arranged in radially opposite positions relative to a rod, each roller traveling along a corresponding longitudinal track parallel to the actuation axis.

[0008] Documents DE102018003877 and EP1123779 describe the use of a pin connected to a centering rod and constrained to slide in an axial guide parallel to the actuation axis.

[0009] On the one hand, known solutions do not always provide sufficient accuracy in maintaining the angular position of the centering rod. Some solutions do not even provide the same reliability for both possible directions of rotation of the centering rod. On the other hand, known solutions result in strong friction when the centering rod is slid between the rest and operating positions, and between the operating and rest positions, leading to partial dissipation of the actuating force provided by the actuator.

[0010] To facilitate maintenance of the centering unit, it is essential to design the unit to allow for actuator replacement, whether pneumatic or electric. In particular, actuator replacement in electric actuation units is complex and difficult. In fact, due to the nature of the drive mechanisms traditionally used in electric centering units, which apply action by rotating a driven rod, special gears are required to convert rotational motion into linear translation of the centering rod. The structural complexity of such actuators and the number of gears involved typically make it difficult to construct connection interfaces that facilitate actuator disassembly and reassembly. Furthermore, to ensure maximum operational efficiency, actuator assembly and disassembly should not alter the coaxial arrangement between the stator and rotor. Summary of the Invention

[0011] In view of the above, the fundamental problem of the present invention is to design a centering unit that can overcome the shortcomings of the prior art.

[0012] In the context of this problem, one object of the present invention is to provide a centering unit that can effectively prevent the centering rod from rotating about the actuation axis without generating significant friction that could lead to the dissipation of most of the actuation thrust supplied to the centering unit.

[0013] Another objective of this invention is to design a centering unit that can effectively resist the rotation of the centering rod in two rotational directions.

[0014] Another object of the present invention is to design a centering unit that allows the actuator to be connected to and disconnected without affecting its performance and wear.

[0015] According to a first aspect, the present invention therefore relates to a centering unit comprising: a housing in which a centering rod is at least partially housed, the centering rod being linearly movable along an actuation axis between a first minimum pull-out position and a second maximum pull-out position from the housing; and an anti-rotation component configured to prevent the centering rod from rotating about the actuation axis during movement of the centering rod between the first and second positions.

[0016] According to the invention, the anti-rotation assembly includes a sliding block fixedly connected to a centering rod and a guide fixedly connected to a housing, wherein the sliding block is constrained to slide along the guide in a direction parallel to the actuation axis by the intervention of at least a pair of rollers, the rollers being arranged side by side, their respective roller shafts being contained in planes parallel to each other and transverse to each other.

[0017] The applicant discovered that a special anti-rotation assembly, featuring a sliding block and guide connected by rollers, effectively prevents the centering rod from rotating about the actuation axis while generating minimal or near-zero friction. This allows for maximum utilization of the actuation thrust provided by the relevant actuator.

[0018] In particular, each of a pair of side-by-side rollers is arranged such that its respective roller shaft lies in a plane that is parallel to and transverse to each other, and is able to resist torsion in a specific direction of rotation, thereby effectively preventing the rod from rotating in both directions.

[0019] The present invention may have at least one of the following preferred features; in particular, these preferred features may be combined with each other as needed to meet specific application requirements.

[0020] Preferably, the sliding block is connected to the guide by at least a plurality of rollers arranged side by side, each roller shaft contained in a plane parallel to each other, wherein each roller shaft is transverse relative to the adjacent roller shaft in an alternating manner.

[0021] In a variation of the invention, the rollers of the at least one pair of rollers are constrained to rotate within a longitudinal seat about their own roller axis, the longitudinal seat extending parallel to the actuation axis and defined by a pair of longitudinal half seats, wherein a first half seat of the pair of longitudinal half seats is formed on the guide-facing wall of the slider and a second half seat of the pair of half seats is formed on the guide-facing wall of the slider.

[0022] Preferably, each longitudinal half-seat has a V-shaped or approximately triangular cross-section that opens on one side.

[0023] In a variation of the invention, at least two connecting elements protrude laterally from the pad toward the interior of the housing and are configured to engage in a set of corresponding receiving seats present on the sleeve of the centering rod.

[0024] Alternatively, the sliding block and the centering rod are formed as a single unit.

[0025] Preferably, the sleeve of the centering rod has at least two sets of receiving seats for accommodating connecting elements, each set of receiving seats including a plurality of seats aligned in a direction parallel to the actuation axis, and each set of receiving seats is disposed at different angular positions on the sleeve of the centering rod.

[0026] In a variant of the invention, the centering unit includes an actuator having an actuator body connected to the housing and configured to act on a control lever constrained to the centering lever. The actuator is configured to cause the control lever to move linearly along a control axis between two end positions, the first of which is a maximum insertion position into the actuator body, and the second position is a minimum insertion position into the actuator body.

[0027] Preferably, the actuator body is removably attached to the bottom wall of the housing.

[0028] The applicant has determined that the removable connection between the actuator body and the housing facilitates the maintenance and replacement of the electric actuator.

[0029] In a variation of the invention, the head wall of the actuator body, which serves as the connection interface for connection with the housing, and the bottom wall of the housing, which serves as the connection interface for connection with the actuator body, are formed in a complementary manner to achieve relative positioning guidance between the actuator body and the housing, such that the drive axis is approximately coincident with the actuator control axis.

[0030] The applicant has determined that the special construction of the head wall of the actuator body, which serves as the connection interface for connection with the housing, and the bottom wall of the housing, which serves as the connection interface for connection with the actuator body (e.g., for achieving relative positioning guidance between the actuator body and the housing), ensures precise positioning relative to the actuation axis of the closing device (coinciding with the actuator control axis), thereby minimizing the friction involved.

[0031] In a variant of the invention, the actuator body includes a guide and centering protrusion that protrudes at least partially from the head wall of the actuator body, which serves as a connection interface for connection with the housing, toward the outside of the actuator body.

[0032] Accordingly, the housing includes a guide opening formed on the bottom wall of the housing, which serves as a connection interface for connection with the actuator body. The guide opening is configured to accommodate and engage guide and centering protrusions within it to achieve relative positioning guidance.

[0033] Advantageously, the presence of guide and centering protrusions on the actuator body makes it easier for the user to position it centered and coaxially relative to the housing of the closing device during assembly. This is further supported by the presence of guide openings on the bottom wall of the housing, which are configured to receive and engage the guide and centering protrusions, thereby resulting in relative positioning between the actuator body and the housing.

[0034] Preferably, at least a portion of the guide port has a cross section that is complementary to at least one cross section of the guide and centering protrusion transverse to the actuation axis.

[0035] More preferably, the complementary at least one cross-sectional portion of the guide port is connected to the guide and centering protrusion by interference or with substantially no clearance.

[0036] Advantageously, the interference fit or virtually no clearance between the guide port and the guide and centering protrusions ensures high precision in the relative positioning between the housing and the actuator body, so as to ensure that the actuation axis of the closing device is substantially coaxial with the actuator drive axis.

[0037] In a variant of the invention, the actuator is electric and includes a cylindrical electromagnetic stator and a cylindrical hollow magnetic rotor located inside the electromagnetic stator and coaxial with the electromagnetic stator, wherein the actuator control axis is the rotation axis of the hollow magnetic rotor.

[0038] Preferably, the first end of the magnetic rotor protrudes from the actuator body at the guide and centering protrusion.

[0039] Preferably, the guide opening is shaped to accommodate a first end that can rotate freely.

[0040] Preferably, the guide and centering protrusion has an extension extending around the protruding end of the magnetic rotor, and more preferably, an extension having axisymmetry with respect to the actuation axis.

[0041] In a variant of the invention, the magnetic rotor is constrained to the actuator body by the intervention of a pair of bearings in a manner that allows it to rotate about the control axis of the electric actuator.

[0042] Preferably, the head wall of the actuator body defines a housing for a first bearing of a pair of bearings, facing inwards from the actuator body.

[0043] Preferably, the bearings of the pair of bearings are arranged generally at or near the head and bottom ends of the actuator body.

[0044] Preferably, the head wall of the actuator body is defined by the head cover of the actuator body.

[0045] More preferably, the housing of the first bearing is formed at the guide and centering protrusion.

[0046] This makes it advantageous to construct actuators in a particularly compact manner.

[0047] In a variation of the invention, the control lever is threaded and fixedly connected to a nut on the magnetic rotor, wherein the nut has an internal thread configured to engage the control lever thread, such that rotation of the nut causes translation of the threaded lever.

[0048] Preferably, the nut is substantially completely contained within the volume defined inside the hollow magnetic rotor, and more preferably, it is located at the first end of the hollow magnetic rotor protruding from the actuator body.

[0049] Advantageously, the internal arrangement of the nut, which is fixedly connected to and / or integrally formed with the hollow magnetic rotor, facilitates a strictly coaxial arrangement of the rotor / nut assembly relative to the stator, thereby minimizing friction and allowing maximum utilization of the torque provided by the electric actuator. In effect, positioning the nut within the rotor prevents all minor displacements that may occur when the actuator is assembled into the housing.

[0050] Furthermore, due to the arrangement of the nut relative to the interior of the hollow magnetic rotor, the rotor can also be supported by a pair of bearings.

[0051] In a variation of the invention, the bottom wall of the housing includes a pair of screw seats arranged symmetrically about the intersection of the actuation axis on the bottom wall.

[0052] Similarly, the actuator body includes a pair of screws that pass through the actuator body parallel to the actuation axis and are arranged at opposite angular positions relative to the actuation axis.

[0053] Advantageously, the symmetrical arrangement of the screw seat and screw allows the electric actuator to be mounted to the housing in a first orientation or a second orientation rotated 180° relative to the first orientation, thereby allowing the drive electronics to be housed on the first or second side relative to the drive body.

[0054] Preferably, the control lever thread is configured to allow reversibility of control lever rotation without a command applied by an electric actuator.

[0055] Conveniently, the suitable thread that allows the control lever to rotate reversibly not only facilitates the installation of the electric actuator into the housing but also facilitates the manual opening of the actuator unit.

[0056] In a variant of the invention, the first end of the hollow magnetic rotor is made in the form of a crown gear with a conical configuration.

[0057] Preferably, the unit further includes a manual drive device configured to apply rotation to the end of the crown gear of the magnetic rotor.

[0058] Advantageously, the shape of the first end of the crown gear rotor and the presence of a manual drive configured to apply rotation to the crown gear allow for direct manual operation of the rotor, facilitate the disassembly and reassembly of the electric actuator to the housing, and apply a fully coaxial action to the actuation axis and the rotation axis.

[0059] More preferably, the first manual drive includes at least one toothed element housed in the housing near the bottom wall of the housing. The toothed element is arranged in the housing in such a way that it is rotatable about an axis transverse to the actuation axis and translatable along the transverse axis to selectively engage the end of the crown gear. The toothed element is configured such that rotation about the transverse axis applied to the toothed element when engaged with the end of the crown gear causes rotation of the magnetic rotor about the rotation axis of the electric actuator.

[0060] Preferably, the toothed element includes a toothed conical head.

[0061] More preferably, the resilient reset device acts on at least one toothed element to return the toothed element to a position of disengagement from the end of the crown gear without being forced into an engaged position.

[0062] The special shape of the manual drive mechanism allows for easy and convenient operation of the rotor using conventional tools such as electric screwdrivers. In practice, the action on the rotor is applied by acting on the toothed element in a direction transverse to the actuation axis to engage it with the rotor and apply rotation to the rotor. Advantageously, once the action on the transverse element ceases, the toothed element independently returns to its resting position, where it is not engaged with the rotor, by means of a resilient reset device.

[0063] In a variation of the invention, the bearings of a pair of bearings are both radial thrust bearings and axial thrust bearings.

[0064] Preferably, a pair of bearings includes a plurality of balls housed in a crown-shaped seat, the seat forming upper and lower abutment portions for ball engagement.

[0065] Conveniently, in this way, the bearing allows the magnetic rotor to rotate while maintaining its position completely coaxial with the actuation axis and resisting the acting axial force, especially when reaching the end position of the drive rod.

[0066] In a variant of the invention, the electromagnetic stator includes a plurality of coils with the winding axes of the coils arranged radially relative to the axis of rotation, and the hollow cylindrical magnetic rotor includes a plurality of permanent magnets arranged on a rotor sleeve, the permanent magnets being parallel to the axis of rotation and having alternating polarities relative to adjacent magnets.

[0067] In a variant of the invention, the unit includes an encoder associated with a hollow cylindrical magnetic rotor, the encoder being configured to monitor the instantaneous position of the rod based on the number of revolutions performed by the rotor. Attached Figure Description

[0068] Further features and advantages of the invention will become clearer from the following detailed description of some preferred embodiments with reference to the accompanying drawings.

[0069] Based on the preceding description, different features in each construction can be combined as needed, as long as there are specific advantages resulting from a particular combination.

[0070] In these attached figures,

[0071] Figure 1 This is a perspective view of the centering unit according to a first preferred embodiment of the present invention;

[0072] Figure 2 yes Figure 1 A cross-sectional view of the centering element in the diagram;

[0073] Figure 2a and Figure 2b They are along Figure 2 A sectional view of the cutting lines BB and CC in the diagram;

[0074] Figure 3 and Figure 3a yes Figure 1 A partial exploded view of the centering element and its magnified details;

[0075] Figure 4 It is in a partially disassembled configuration. Figure 1 A perspective view of the centering unit; and

[0076] Figure 5 This is the configuration viewed from below after the electric actuator has been removed. Figure 1 A perspective view of the housing of the centering unit in the diagram;

[0077] Figure 6a and Figure 6b This is a partial cross-sectional view of the centering unit according to the second preferred embodiment, wherein actuation electronics are respectively mounted on the first side and the second side;

[0078] Figure 7 This is a cross-sectional view of the centering unit according to a third preferred embodiment of the present invention; and

[0079] Figure 8 , Figure 8a , Figure 9 and Figure 9a They are along Figure 7 Partial sectional view and magnified details of section lines aa and bb in the diagram. Detailed Implementation

[0080] For the sake of illustration, the same numbers or symbols are used in the following description to represent construction elements with the same function. Furthermore, for clarity, some reference numerals may not be repeated in all figures.

[0081] While various modifications and alternative constructions can be made to the invention, certain preferred embodiments are illustrated in the accompanying drawings and described in detail below. It must be understood, in any case, that the invention is not intended to be limited to the specific embodiments illustrated, but rather is intended to cover all modifications, alternatives, and equivalent constructions falling within the scope of the invention as defined in the claims.

[0082] The use of “for example,” “etc.”, and “or” indicates a non-exclusive alternative without limitation, unless otherwise stated. The use of “includes” and “contains” means “includes or contains, but is not limited to”, unless otherwise stated.

[0083] refer to Figures 1-5The diagram shows a centering unit according to a first preferred embodiment of the present invention, which is generally represented by the numeral 10.

[0084] The centering unit 10 includes a housing 11, and a centering rod 13 is movably at least partially housed within the housing. The centering rod 13 is capable of linear movement along an actuation axis A between two end positions: a first minimum pull-out position and a second maximum pull-out position from the housing 11.

[0085] The centering unit 10 also includes an actuator 20, which is provided with an actuator body 23, which is removably connected to the housing 11 at the bottom wall 11c of the housing 11.

[0086] Actuator 20 is configured to act on control lever 14, which is constrained to centering lever 13. Specifically, actuator 20 is configured to move control lever 14 linearly along control axis (specifically coinciding with actuation axis A) between two end positions, which are a first maximum insertion position and a second minimum insertion position in actuator body 23.

[0087] To prevent the centering rod 13 from rotating around the actuation axis A, the centering rod 13 is slidably connected to the housing 11 by the anti-rotation assembly 40, such as... Figure 2a , Figure 2b , Figure 3 and Figure 3a As shown in detail. The anti-rotation assembly 40 includes a sliding block 41 fixedly connected to the centering rod 13 and a guide 42 fixedly connected to the housing 11, wherein the sliding block 41 is constrained to slide within the guide 42.

[0088] In the first embodiment shown, the centering rod 13 is connected to the sliding block 41 by a plurality of fasteners 45 (such as screws, which engage the sliding block 41 and are fitted into corresponding threaded seats 45a formed in the centering rod 13). Furthermore, at least two connecting elements 43 protrude from the sliding block 41 toward the interior of the housing 11 in a direction transverse to the actuation axis A and are spaced apart from each other in a direction parallel to the actuation axis A. The connecting elements 43 may be made, for example, in the form of a pivot, pin, or plate, or equivalents thereof.

[0089] The connecting element 43 is configured to engage in a set of corresponding seats 44, which are accessible from the sleeve of the centering rod 13 and extend into the centering rod 13 in a direction transverse to the actuation axis A. The seats 44 of the connecting elements are also spaced apart from each other in a direction parallel to the actuation axis A, specifically by the same distance as the connecting elements 43, so that each connecting element 43 can engage in its corresponding seat 44. In this way, the connection between the sliding block 41 and the centering rod 13 is stronger than any torque applied to the centering rod 13.

[0090] Specifically, the centering rod 13 includes at least two sets of seats 44 complementary to the connecting element 43. Preferably, each set of seats 44 is positioned at different angular locations on the sleeve of the centering rod 13, for example, a first position rotated 90° relative to a second position about the actuation axis A. In this way, the centering rod 13 can be coupled to the sliding block 41 in at least two predetermined orientations, for example, in a first orientation, the centering rod 13 rotated 90° relative to a second orientation about the actuation axis A. Accordingly, there are at least two sets of threaded seats 45a for engaging the fastener 45 in at least two predetermined orientations.

[0091] The sliding block 41 is slidably connected to the guide 42 in a direction parallel to the actuation axis A by the intervention of at least a pair of rollers 46.

[0092] Preferably, the sliding block 41 is connected to the guide 42 through the intervention of at least one set of multiple rollers 46, or as... Figure 3a The details are shown in the diagram, which connects to the guide via the intervention of two sets of multiple rollers 46.

[0093] In a first embodiment of the invention, the sliding block 41 is connected to the guide 42 by the intervention of two sets of multiple rollers 46, and the guide 42 includes a pair of half guides 42a. In each set of multiple rollers, the rollers 46 are arranged side by side, their respective roller shafts being contained in planes parallel to each other, wherein, in an alternating manner, each roller shaft is transverse, for example or orthogonal, relative to the adjacent roller shaft.

[0094] Each set of multiple rollers 46 is constrained to rotate within a corresponding longitudinal seat 47 about its own roller axis, the longitudinal seat extending parallel to the actuation axis A. Each longitudinal seat 47 is defined by a pair of longitudinal halves 47a, 47b, each half having a V-shaped or generally triangular cross-section open on one side, wherein the first half 47a of the pair is formed on a corresponding sidewall of the slider 41 facing the guide 42, and the second half 47b of the pair is formed on a corresponding inner wall of the guide 42 facing the slider 41. In the illustrated embodiment, the half-guide 42a of the guide 42, together with the slider 41, defines the corresponding longitudinal seat 47.

[0095] Actuator 20 is typically pneumatic or electric. In the specific case of the illustrated embodiment, actuator 20 is electric. However, the principles of the invention are equally applicable to centering units operated by pneumatic actuators.

[0096] The electric actuator 20 is a hollow shaft type, such as a torque motor, and includes a cylindrical electromagnetic stator 21, which is fixedly constrained to the actuator body 23. The electromagnetic stator 21 cooperates with a corresponding hollow magnetic rotor 24, which is also cylindrical and arranged coaxially inside the electromagnetic stator 21. The magnetic rotor 24 is configured to rotate about the control axis of the electric actuator 20. Power is supplied to the electromagnetic stator 21 via drive electronics 30 mounted on the side of the actuator body 23.

[0097] Preferably, the electromagnetic stator 21 includes a plurality of coils (not shown), each coil having a winding axis that is radial relative to the actuation axis A. The hollow magnetic rotor 24 includes a plurality of permanent magnets (not shown) with elongated shapes, such as tile-shaped or parallelepiped-shaped, arranged on a cylindrical sleeve, parallel to the actuation axis A, and having alternating polarities relative to adjacent permanent magnets.

[0098] The magnetic rotor 24 is axially constrained to the actuator body 23 by the intervention of a pair of bearings 31, 32, which are generally arranged at or near the head and bottom ends of the actuator body 23. Each end of the actuator body 23 is preferably closed by a corresponding head cover 25 and a bottom cover 27, wherein the head cover 25 defines a head wall 25b that externally defines the actuator body 23 at the top, and the bottom cover 27 defines a bottom wall that externally defines the actuator body 23 at the bottom.

[0099] A nut 22 is also provided, which is fixedly constrained to the hollow magnetic rotor 24. The nut 22 has an internal thread configured to engage the control rod 14, such that rotation of the nut 22 caused by the cylindrical rotor 24 results in translation of the threaded control rod 14. For this purpose, the control rod 14 has threads on its outer sleeve.

[0100] Conveniently, the nut 22 is housed inside the hollow magnetic rotor 24, preferably so that it is substantially completely enclosed within the hollow magnetic rotor 24.

[0101] In the illustrated embodiment, a nut 22 is disposed inside a hollow magnetic rotor 24, which protrudes from the actuator body 23 at a first end 24a, and the nut is held inside the rotor 24 by an annular nut 26. Specifically, the first end 24a of the rotor 24 protrudes from the actuator body 23 at a head cover 25, which closes the body 23 at the top and serves as a connection interface for connection with the housing 11.

[0102] In a feasible variant of the invention not shown, the hollow magnetic rotor 24 has an internal thread configured to engage the threaded control rod 14, with the hollow magnetic rotor itself acting as a nut.

[0103] The threaded control rod 14 is permanently and coaxially connected to the first end of the centering rod 13. In an alternative embodiment not shown, the control rod 14 is integrally formed with the centering rod 13.

[0104] Advantageously, the housing 11 and the actuator body 23 are formed in a complementary manner to form centering guides relative to each other, thereby facilitating the installation or replacement of the electric actuator 20 relative to the housing 11.

[0105] For this purpose, such as Figure 4 As clearly visible, the head wall 25b of the actuator body 23 has at least one guide and centering protrusion 25a extending outward toward the actuator body 23. Preferably, the guide and centering protrusion 25a has an extension that is axially symmetrical with respect to the actuation axis A, such as a cylindrical extension centered on the actuation axis A, or an extension having multiple concentric cylinders of different diameters centered on the actuation axis A. The guide and centering protrusion 25a extends around the protruding end 24a of the magnetic rotor 24, preferably in contact with it.

[0106] In a complementary manner, the housing 11 has a guide opening 37 formed on its bottom wall 11c. Figure 5 As shown in the diagram, the guide port serves as a connection interface for connection with the actuator body 23. The guide port 37 is shaped to accommodate at least a portion of the first protruding end 24a of the magnetic rotor 24 and the guiding and centering protrusion 25a. Specifically, the first protruding end 24a of the magnetic rotor 24 can be accommodated (and in the assembly configuration) in the guide port 37 without contact, so as to allow free rotation. Conversely, the guiding and centering protrusion 25a can be accommodated (and in the assembly configuration) in the guide port 37 with interference or substantially no play, so as to achieve substantially precise centering between the actuation axis A and the actuator control axis 20.

[0107] In the first embodiment shown, the head cover 25 advantageously defines a housing for the first bearing 31 of a pair of bearings 31, 32. In particular, the housing for the first bearing 31 is advantageously located at the guide and centering protrusion 25a, but arranged on the opposite side relative to the head wall 25b defined by the outside of the cover 25, i.e., it faces the interior of the actuator body 23.

[0108] Therefore, the first bearing 31 is generally arranged near the first end 24a of the magnetic rotor 24. The first bearing 31 is housed in a seat defined by the head cover 25 by the intervention of a washer 38 to enhance the insulation and protection of the actuator body 23.

[0109] Similar to the first bearing 31, the second bearing 32 of the pair of bearings 31, 32 is located at the second end 24b of the magnetic rotor 24 opposite to the first end 24a, approximately at the bottom end of the actuator body 23.

[0110] Preferably, both the first bearing 31 and the second bearing 32 are radial and axial thrust type. In the illustrated embodiment, bearings 31, 32 include a plurality of balls 33 housed in a crown-shaped seat 34 to create upper and lower abutment portions for engagement of the balls 33.

[0111] The bottom cover 27 of the actuator body 23 carries an encoder 28 for monitoring the instantaneous position of the control lever 14, which depends on the number of revolutions of the rotor 24 detected by the encoder 28. For this purpose, the magnetic rotor 24 carries a magnet 29 at its second end 24b, opposite to the first end 24a.

[0112] The centering unit 10 also includes a manual drive device 16 for driving the rotor 24. For this purpose, the first end 24a of the rotor 24, protruding from the actuator body 23, is formed in the form of a conical crown gear, and the manual drive device 16 is configured to impart rotation to the crown gear end 24a of the magnetic rotor 24. In particular, in the illustrated embodiment, the manual drive device 16 includes a toothed element 16a, which is housed in the housing 11 near the bottom wall 11c.

[0113] The toothed element 16a is housed in the housing 11 such that its first end terminates approximately at the toothed crown element 24a, and its second end faces the side from an opening 11b provided on the housing 11. At the first end, the toothed element 16a is provided with a toothed conical head configured to engage with the toothed crown end 24a of the rotor 24.

[0114] The toothed element 16a is arranged in the housing 11 and is movable in a transverse direction to the actuation axis A between a position disengaged from the toothed crown end 24a and a position engaged with the toothed crown end 24a. In the engaged position, rotation of the toothed element 16a about the transverse axis causes the rotor 24 to rotate about the actuation axis A, and thus causes the control lever 14 to translate along the actuation axis A.

[0115] A corresponding elastic reset device (not shown) acts on the toothed element 16a to bring the toothed element 16a to a position disengaged from the rotor 24 when it is not forced into the engaged position.

[0116] Figure 4The disassembled centering unit 10 according to the first embodiment is shown, i.e., the electric actuator 20 is removed from the housing 11, for example, for replacement or maintenance of the electric actuator 20. As can be seen from this figure, the control lever 14 can be removed from the electric actuator 20, but remains constrained to the housing 11. The removal of the lever 14 is achieved by rotating the magnetic rotor 24 and determining the relative translation between the lever 14 and the rotor 24 in this way. Once the toothed element 16a is engaged with the toothed crown end 24a of the rotor 24, this rotation can be easily applied by the toothed element.

[0117] Mounting the electric actuator 20 onto the housing 11 also requires rotating the magnetic rotor 24. Once the maximum insertion position is reached, the protrusion 25a serves to guide and center between the housing 11 and the electric actuator 20, thereby allowing the two components to be fixed together in a configuration with perfect alignment between the control lever 14 and the control axis of the actuator 20.

[0118] According to a second embodiment of the present invention, the electric actuator 20 can be mounted on the housing 11 in two different configurations, namely, the driving electronics 30 is arranged on a first side or a second side opposite to the first side relative to the driving body 11, such as... Figure 6a and Figure 6b As shown. For this purpose, the actuating body 11 includes two screw seats 11d, which are arranged symmetrically on the bottom wall 11c with respect to the intersection of the actuation axis A on the bottom wall 11c. This allows a pair of screws 27b to be screwed into the screw seats 11d, which pass through the actuator body 23 parallel to the actuation axis A and are arranged at equidistant positions relative to the actuation axis A but offset by 180° relative to the actuation axis.

[0119] Figure 7 , Figure 8 , Figure 8a , Figure 9 and Figure 9a A third embodiment of the centering unit 10 of the present invention is shown, wherein the centering rod 13 is slidably connected to the housing 11 by an anti-rotation assembly 40, the anti-rotation assembly including a sliding block 41 fixedly connected to the centering rod 13 and a guide 42 fixedly connected to the housing 11, wherein the sliding block 41 is constrained to slide along the guide 42.

[0120] Specifically, the sliding block 41 is connected to the guide 42 by the intervention of a single set of multiple rollers 46, such as a pair of rollers 46, arranged side by side, their respective roller shafts contained in planes parallel to each other, wherein, in an alternating manner, each roller shaft is transverse, for example orthogonal, relative to the adjacent roller shaft, as from Figure 8a and Figure 9a As can be seen from the comparison.

[0121] Similarly, in this case, the rollers of the plurality of rollers 46 are constrained to rotate within a longitudinal seat 47 about their own roller axis, the longitudinal seat extending parallel to the actuation axis A.

[0122] like Figure 8 and Figure 9 As shown, the longitudinal seat 47 is defined by a pair of longitudinal half seats 47a, 47b, which have a V-shaped or approximately triangular cross-section and are open on one side. The first half seat 47a of the pair of half seats is formed on the side wall of the sliding block 41 facing the guide 42, and the second half seat 47b of the pair of half seats is formed on the wall of the guide 42 facing the sliding block 41.

[0123] In a third embodiment of the invention, the guide 42 is located between the wall of the housing 11 and the sliding block 41, and the sliding block 41 is located between the guide 42 and the centering rod 13 to which the sliding block is constrained.

Claims

1. A centring unit (10), comprising: a housing (11) in which a centring rod (13) is at least partially housed, the centring rod being linearly movable along an actuation axis (A) between a first minimum extracted position from the housing (11) and a second maximum extracted position from the housing (11); and an anti-rotation assembly (40) configured to prevent the centring rod (13) from rotating about the actuation axis (A) during the movement of the centring rod between the first position and the second position; characterised in that the anti-rotation assembly (40) comprises a sliding block (41) fixedly connected to the centring rod (13) and a guide (42) fixedly connected to the housing (11), wherein the sliding block (41) is constrained to slide along the guide (42) in a direction parallel to the actuation axis (A) by the intervention of at least one pair of rollers (46) arranged side by side, the respective roller axes of which are contained in planes parallel to each other and transverse to each other.

2. The centering unit (10) according to claim 1, wherein The sliding block (41) is coupled to the guide (42) by means of at least a plurality of rollers (46) arranged side by side, the respective roller axes of which are contained in planes parallel to each other, wherein in an alternating manner, each roller axis is transverse with respect to the adjacent roller axes.

3. The centering unit (10) according to claim 1 or 2, wherein The rollers of said at least one pair of rollers (46) are constrained to each rotate about their respective roller axes within longitudinal seats (47) extending parallel to the actuation axis (A), the longitudinal seats (47) being defined by a pair of longitudinal half-seats (47a, 47b), wherein a first half-seat (47a) of the pair of longitudinal half-seats is formed on a wall of the sliding block (41) facing the guide (42) and a second half-seat (47b) of the pair of half-seats is formed on a wall of the guide (42) facing the sliding block (41).

4. The centering unit (10) according to claim 3, wherein Each longitudinal half-seat (47a, 47b) has a V-shaped or substantially triangular cross-section open on one side.

5. Centering unit (10) according to any one of the preceding claims, wherein At least two connecting elements (43) protrude from the sliding block (41) transversely towards the inside of the housing (11) configured to engage into a respective set of containment seats (44) present on a sleeve of the centring rod (13).

6. The centering unit (10) according to claim 5, wherein There are at least two sets of containment seats (44) for accommodating the connecting elements (43) on the sleeve of the centring rod (13), each set of containment seats (44) comprising a plurality of seats aligned in a direction parallel to the actuation axis (A), each set of containment seats (44) being arranged at a different angular position on the sleeve of the centring rod (13).

7. The centering unit (10) according to any one of claims 1 to 4, wherein The sliding block (41) is integral with the centring rod (13).

8. The centering unit (10) according to any one of the preceding claims, comprising an actuator (20) provided with an actuator body (23) connected to the housing (11) and configured to act on a control lever (14) which is in turn constrained to the centering lever (13), wherein, The actuator is configured to linearly move the control rod (14) along a control axis between two end positions, a first position of the two end positions being a maximum insertion position into the actuator body (23) and a second position being a minimum insertion position into the actuator body (23).

9. The centering unit (10) according to claim 8, wherein The actuator body (23) is removably connected to the housing (11) at a bottom wall (lie) thereof.

10. Centering unit (10) according to claim 8 or 9, wherein The head wall (25b) of the actuator body (23) which acts as a connection interface with the casing (11) and the bottom wall (11c) of the casing (11) which acts as a connection interface with the actuator body (23) are shaped in a complementary manner so as to achieve a relative positioning guide between the actuator body (23) and the casing (11) such that the drive axis (A) substantially coincides with the actuator control axis (20).

11. The centering unit (10) according to any one of claims 8 to 10, wherein The actuator body (23) comprises a guide and centering protrusion (25a) which protrudes at least partially towards the outside of the actuator body (23) from the head wall (25b) of the actuator body (23) which acts as a connection interface with the casing (11).

12. The centering unit (10) according to claim 11, wherein The casing (11) comprises a guide mouth (37) formed on the bottom wall (11c) of the casing (11) which acts as a connection interface with the actuator body (23), configured to house and mate the guide and centering protrusion (25a) inside it so as to achieve a relative positioning guide.

13. The centering unit (10) according to claim 12, wherein The guide mouth (37) has at least one cross-sectional portion which is complementary to the cross section of the guide and centering protrusion (25a) transversely to the actuation axis (A).

14. The centering unit (10) according to claim 13, wherein The complementary at least one cross-sectional portion of the guide mouth (37) is coupled with the guide and centering protrusion (25a) with interference or substantially without play.

15. The centering unit (10) according to any one of claims 10 to 14, wherein The bottom wall (11c) of the casing (11) comprises a pair of screw seats (11d) arranged symmetrically centered with respect to the intersection on the bottom wall (11c) of the actuation axis (A).

16. The centering unit (10) according to any one of claims 8 to 15, wherein The actuator body (23) comprises a pair of screws (27b) which pass through the actuator body parallel to the actuation axis (A) and are arranged at opposite angular positions with respect to the actuation axis (A).

17. The centering unit (10) according to any one of claims 8 to 16, wherein The actuator (20) is of the electric type and comprises a cylindrical electromagnetic stator (21) and a cylindrical hollow magnetic rotor (24) located inside and coaxial to the electromagnetic stator (21), the actuator control axis being the rotation axis of the hollow magnetic rotor.

18. The centering unit (10) according to claim 17, wherein A first end (24a) of the magnetic rotor (24) protrudes from the actuator body (23) at the guide and centering protrusion (25a).

19. The centering unit (10) according to claim 18, wherein The guide mouth (37) is shaped to accommodate the first end (24a) which protrudes from the magnetic rotor (24) and is free to rotate.

20. The centering unit (10) according to claim 18, wherein The magnetic rotor (24) is constrained to the actuator body (23) in a manner such as to be able to rotate around the control axis of the electric actuator by the intervention of a pair of bearings (31, 32), wherein the head wall (25) of the actuator body (23) defines a housing seat of a first bearing (31) of the pair of bearings (31, 32), the housing seat of the first bearing facing the inside of the actuator body (23), preferably the housing seat of the first bearing being formed at the guide and centering protrusion (25a).

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