FR2852307A1 - Gear head for linear guiding device, has body formed of two halves, where body accommodates attack pulley and where each halves are symmetrical with respective plane - Google Patents

Abstract

The head has a body formed of two halves (16a, 16b) and designed to accommodate an attack pulley (14) with support units (13a, 13b). The half (16a) is symmetrical with respect to a plane perpendicular to a rotation axis of the pulley. The half (16b) is symmetrical with respect to another plane that is perpendicular to a rotation axis of the former plane and passing through the rotation axis of the pulley.

Description

DESCRIPTION

  The present invention relates to a linear guide device, of the type comprising a linear beam having guide means oriented parallel to the longitudinal axis of the beam, sliding means 5 able to slide along said beam guide means, and a flexible transmission unit, able to move said sliding means in the direction of the longitudinal axis of the beam, where the transmission unit comprises a belt intended to drive said sliding means along the axis of the beam, a motor unit capable of controlling the rotation of an attack pulley and a return group provided with a driven pulley and a tensioning device.

  More particularly, the invention relates to a driving head intended to be fixed to one end of the rectilinear beam in order to receive, while supporting it in rotation, said driving pulley and to provide fixing for a motor group able to control in rotation the attack pulley.

  Linear guide devices of the type specified above are commonly adopted in the field of industrial automation for controlling the axial movement of a carriage, or a group of carriages, on which operator heads, manipulators can be mounted. or the like.

  According to the known technique, the envelope of the drive head of these linear guide devices, in which the driving pulley is housed, is produced in a single piece, with expensive manufacturing methods, for example by machining on machine tool or by stamping. In addition, the driving pulley received inside the casing of the drive head is mounted on the output shaft of the power unit, by means of connection devices, which allow the pulley to be set on a diameter single tree. In order to be able to use a power unit having an output shaft of different diameter, it is therefore necessary to use a different pulley. This however obliges the manufacturer of the linear guide device to have pulleys of different internal diameters in stock, with a view to the possibility of having to mount motor units having different shaft diameters.

  An object of the present invention is to provide a drive head of simpler structure and which can be produced at lower costs, compared to the drive heads of current manufacture.

  This objective is fully achieved according to the invention thanks to a driving head for a linear guide device comprising a beam provided with guide means, oriented in the direction of the longitudinal axis of the beam, sliding means able to slide. along said guide systems and a transmission unit adapted to move said sliding means along the guide means, where said transmission unit comprises a belt member intended to move said sliding means, a driving pulley able driving said belt member 25 and a motor unit capable of controlling the driving pulley in rotation, the driving head comprising a casing intended to be fixed to one end of the beam and to accommodate the driving pulley with respective support elements, said envelope 30 comprising two symmetrical halves, both with respect to a first plane perpendicular to the axis of rotation of the driving pulley only with respect to a second plane perpendicular to the first and passing through the axis of rotation of the pulley, said halves being fixed to each other so as to form a body in which are accommodated the driving pulley and the support elements; and said envelope further comprising two outer plates, or flanges, each fixed to one of said halves, so as to close the body of the head by parts axially opposite with respect to the driving pulley.

  The invention also proposes to produce a drive head provided with an attack pulley capable of being wedged on at least two different diameters of the output shaft of the power unit. Another objective of the invention consists in producing a drive head provided with a drive pulley capable of being wedged simultaneously on two shafts, for example, an output shaft of the power unit and a shaft for transmitting the rotary movement to the driving pulley of the drive head of a second linear guide device, mounted in parallel with the first, or else a transducer shaft intended to take up the angular speed of the driving pulley.

  These other objects are achieved according to the invention, thanks to a drive head for a linear guide device, the driving pulley of which has a pair of internal coaxial cylindrical cavities capable of each accommodating a respective wedging device, so that the pulley can be wedged simultaneously on two shafts.

  In short, the invention is based on the idea of producing a driving head for a linear guide device having an envelope formed by two halves symmetrical both with respect to a first plane, perpendicular to the axis of rotation of the pulley that, with respect to a second plane perpendicular to the first and passing through the axis of rotation of the pulley, said halves being able to be fixed to each other to form a body, in which is rotatably supported the attack pulley, 35 and a pair of side plates, or flanges, able to close the body of the head, by parts opposite to the pulley, and to allow fixing for the group motor intended to actuate the driving pulley.

  Preferably, the two halves of the body of the drive head are produced by extrusion in the direction of the axis of rotation of the driving pulley, that is to say transversely to the longitudinal direction of the beam of the device. linear guide.

  According to another aspect of the invention, in order to allow the setting of the driving pulley on two different output shaft diameters of the power unit, the driving pulley has a pair of coaxial cylindrical internal cavities of different diameters, each capable of accommodating a wedging device relating to a given shaft diameter.

  The characteristics and advantages of the present invention will appear more clearly in the detailed description which follows, given by way of nonlimiting example with reference to the accompanying drawings, in which: - Figure 1 is a perspective view which shows a portion end of a linear guide device provided with a driving head according to the invention; - Figure 2 is a side elevational view of the linear guide device of Figure 1; - Figure 3 is a vertical cross-sectional view of the drive head of the invention, along the plane III-III of Figure 2; FIG. 4 is a view in transverse vertical section of the drive head of the invention, according to the plane IV-IV of FIG. 2; - Figure 5a is a vertical cross-sectional view of the drive head of the invention, along the plane VV of Figure 2 in which is illustrated the mounting of the driving pulley on a first diameter 35 of the output shaft a power unit; - Figure 5b is a vertical cross-sectional view of the drive head of the invention, along the plane VV of Figure 2, in which is illustrated the mounting of said driving pulley of Figure 5a on a second diameter d 'motor unit output shaft; - Figure 6 is an exploded perspective view of the drive head illustrated in the preceding figures; - Figure 7 is a view similar to that of Figures 5a and 5b, relating to a second embodiment of a drive head according to the invention, and Figure 8 is an exploded perspective view of the drive head of Figure 7; Referring initially to Figures 1 to 6, 15 is generally indicated by 10 a drive head for a linear guide device according to a first embodiment of the invention, able to be mounted at one end of a straight beam 11 (partially illustrated), for driving in motion a flexible transmission member 12, such as a toothed belt. In a manner known per se, the drive head 10 receives and supports in rotation, on a pair of support elements 13a, 13b, such as ball bearings, an attack pulley 14 able to drive the belt 12 at 25 movement. The driving pulley 14 is wedged on an output shaft (known per se and not illustrated) of a motor unit (also not illustrated), in general an electric gear motor, in order to be controlled in rotation by the latter. The power unit is pre-equipped 30 to be mounted in a manner known per se, for example by means of screws 15, on a side of the drive head 10, with its own drive shaft aligned with the axis of rotation of the driving pulley 14.

  According to the invention, the drive head 10 comprises a body formed by two halves 16a and 16b, symmetrical, both relative to a first plane perpendicular to the axis of rotation of the driving pulley 14, as compared to a second plane perpendicular to the first and passing through the axis of rotation of the pulley 14, where this body is intended to accommodate the pulley 14 with its support elements 13a, 13b; and A pair of side plates 17a and 17b, or flanges, able to close the body 16a, 16b by opposite parts with respect to the driving pulley 14 and to allow fixing for the power unit, intended to control in rotation of the pulley 14 and possibly also for an angular position / speed transducer (of a type known per se and not illustrated) associated with the pulley 14.

  The two halves 16a, 16b forming part of the body of the head 10 are fixed to each other by means of threaded connection members (Figures 3 and 4), for example by means of pairs of screws 18a, 18b inserted in respective pass-through non-threaded orifices 19a, 19b and 20 screwed by opposite parts into respective internally threaded sockets 20, locked in respective cylindrical housings 21 formed partly from one half 16a and partly from the other half 16b.

  Said screws 18a, 18b are also used for fixing the two flanges 17a, 17b to the respective halves 16a, 16b of the body of the head 10.

  Each half 16a, 16b has a first axially outer cylindrical housing 22a, 22b into which is inserted, preferably with interference, the outer ring 30 of the respective bearing 13a, 13b and a second axially inner cylindrical housing 23a, 23b able to accommodate the attack pulley 14.

  Once assembled, the drive head 10 can be mounted at one end of the beam 11 of the linear guide device, using for example a fixing plate 24, designed to be fixed to the beam 11 by means of screws 25 and to the head 10 by means of screws 26 (FIG. 6). The fixing plate 24 obviously has a pair of rectangular passing cavities 27, respectively upper and lower, intended to be crossed by the two branches of the belt 12.

  Given their symmetrical structure, the two halves 16a, 16b of the drive head 10 are completely interchangeable with each other, which makes it possible to reduce the production costs of the head. Advantageously, the two halves 16a, 16b have a shape such that they can be produced by extrusion with an extrusion direction corresponding to the axis of rotation of the driving pulley 14, or else to the axis of the housings. cylindrical 22a, 22b and 23a, 23b.

  Advantageously, the two flanges 17a, 17b are initially made symmetrically (with respect to the same planes of symmetry as the two halves 16a, 16b), so that they can be indifferently mounted on one side or the other of the head 10. It is only afterwards, once the motor model which has to be mounted on one of the flanges has been known (in the example illustrated, the flange 17a), that the holes are made for the latter. fixing screw 15 and that a central opening 28 is provided in the center intended to be crossed by the motor output shaft. It is the same for the other flange, in the case where it must be crossed by another shaft (of an angular position / speed transducer or another drive head connected in parallel to the first) or in the case where an angular position / speed transducer has to be mounted thereon.

  By virtue of the fact that the two halves 16a, 16b of the head receive either the pulley 14 or the support elements 13a, 13b, once the body of the head formed by the two halves 16a, 16b has been assembled, it it is possible to assemble and disassemble the motor unit or to reverse its position (from one side to the other of the head) without the need to disassemble the pulley or the support elements and to separate the two halves . This ensures over time the correct mounting of the pulley and its support elements in the head.

  Referring now in particular to FIGS. 5a and 5b, the driving pulley 14 is mounted on the output shaft of the power unit associated with the drive head 10, preferably by means of a 10-element chocking device. conical, of a type known per se, indicated overall by 29.

  The wedging device 29 basically comprises a first element 30 and a second element 31, able to be tightened one on the other by means of clamping screws 32. The first element 30 integrally forms a tubular portion 33 which has inside an axial cylindrical cavity 34 in which one can insert by interference the output shaft of the motor unit and externally a frustoconical surface 35, 20 and an annular flange 36 in which are made non-threaded through holes 37 for the insertion of the clamping screws 32. The second element 31 is a tubular element which has inside a frustoconical cavity 38 able to be fitted and slide 25 on the outer frustoconical surface 35 of the first element 30 and at outside a cylindrical surface 39 of diameter corresponding to that of the flange 36 of the first element 30. In the second element 31 are made orifices threaded loops 40 into which 30 are tightened the clamping screws 32.

  In order to allow the setting of the driving pulley 14 on at least two different shaft diameters, by means of a wedging device of the type described above, the pulley 14 has a pass-through internal cavity formed of a first cylindrical orifice 41 'and a second cylindrical orifice 41' 'of smaller diameter than the first. In the annular portion of pulley which surrounds the hole of smaller diameter 41 '', a series of pass-through holes 42 are provided (two of which are visible in the sectional view of FIG. Sa) for the clamping screws 32 of the wedging device 29.

  In FIG. Sa, an example of the use of the wedging device 29 is illustrated to wedge the driving pulley 14, on a diameter of the output shaft of the power unit roughly equal to that of the second cylindrical orifice 41 ′ 'of the pulley. In this case, the pulley 14 is mounted in the head 10 with its first cylindrical orifice 41 'oriented towards the engine group and a wedging device 29 is used, able to be inserted between the output shaft of the engine group and port 41 '. By tightening the clamping screws 32, the second element 31 of the wedging device is tightened axially against the first element 30 and, thanks to the interaction between its frustoconical surface 38 and the frustoconical surface 35 of the first element 30, it engages by radial forcing the orifice 41 'of the pulley 14.

  Advantageously, the wedging device 29 is produced so as to reduce to zero the axial displacement of the pulley, relative to the shaft in the assembly phase, thereby eliminating the risk of errors in axial positioning.

  In the case of wedging the driving pulley 14 on a shaft with a diameter smaller than that of the second cylindrical orifice 41 '' of the pulley (FIG. 5b), the pulley 14 is mounted in the head 10 with the orifice 41 '' oriented towards the motor unit, in order to allow the mounting of the wedging device 29 between the motor shaft and the orifice 41 ''. In this second case, obviously, it is necessary to use a different type of wedging device, the operation of which is in any case similar to that previously illustrated and will therefore not be described in detail.

  The use of a shimming device as described above, for shimming the driving pulley on the output shaft of the power unit, makes it possible to offer a series of advantages, such as, for example, the ease mounting (since the shaft is locked on the opposite side to the motor unit, by tightening the clamping screws), automatic centering and the correct axial positioning of the pulley on the shaft, in addition to the moment high transmissible torsion.

  By turning the head 10 provided with a body 16a, 16b and flanges 17a, 17b of 180 on itself, or alternatively by changing the position of the latter, it is possible to obtain the following different mounting configurations: a) by turning the complete head through 1800, the fixing side of the motor unit is reversed, without however modifying the setting diameter; b) by turning the flanges alone by 1800, the fixing side of the motor unit is reversed and the setting diameter is varied; and c) by turning the single body formed by the two halves by 1800, the setting diameter is changed, but not the fixing side of the power unit.

  It is also possible, according to another mounting example (not illustrated), to wedge the driving pulley 14 simultaneously on two different shafts (for example on the output shaft of the power unit and on a transmission shaft for a second driving head or on a shaft of an angular position / speed transducer), using for each shaft a suitable wedging device 29.

  Then, with reference to FIGS. 7 and 8, a second embodiment of a drive head according to the invention will be described, in which parts and elements 11 identical to those previously illustrated have been indicated with the same numbers. reference. Ultimately, this second embodiment differs from the first, by the shape of the driving pulley and the wedging device, which are in any case also pre-equipped in this case to allow the pulley to be wedged simultaneously on two shafts distinct (usually of different diameter).

  Referring to FIGS. 7 and 8, a drive head 10 10 for a linear guide device receives an attack pulley 14 supported in rotation by means of bearings 13a, 13b and wedged on a first and a second shaft 50 and 51, for example an output shaft of a motor unit 65 and respectively a shaft for transmitting the movement to a driving pulley (not shown) of a drive head of a second linear guide device, mounted in parallel with the first.

  The structure of the body of the drive head 10 is substantially identical to that of the first embodiment 20 previously illustrated, with reference to Figures 1 to 6 and will therefore not be described in detail.

  On the other hand, we will describe in detail the drive pulley 14 and a pair of shimming devices 29a and 29b, intended respectively for shimming the pulley on the crankshaft 50 and on the transmission shaft 51.

  As can be seen in the sectional view of Figure 7, the driving pulley 14 has a first internal cavity for the shaft 50, comprising a first cylindrical centering hole 52a, into which one can insert with a clearance an end portion of the shaft 50 and a second cylindrical orifice 53a of diameter greater than the first, intended to receive the first wedging device 29a. On an axially opposite side, the pulley 14 has a second internal cavity 35 for the shaft 51 comprising a first cylindrical centering orifice 52b into which one can insert, with a clearance, an end portion of the shaft 51 and a second cylindrical orifice 53b of greater diameter than the first, intended to accommodate the second wedging device 29b.

  In the hub of the driving pulley 14, a series of through holes 54 are formed (only one of which is visible in the sectional view of FIG. 7) for the insertion of first clamping screws 55 for one two wedging devices 29a, 29b (in example 10 illustrated, the first wedging device 29a). In the hub of the pulley 14, a series of threaded blind holes 56a, 56b for the screwing of second clamping screws 57 for the other of the two wedging devices 29a, 29b (in the illustrated example, the second device 15 wedging 29b), are further produced, in an angularly offset position relative to the orifices 54 and by axially opposite parts of the pulley, Each of the two wedging devices 29a, 29b comprises: At least one forcing ring S8a, 58b (in the example illustrated, two axially adjacent rings) which can be inserted into the annular housing defined between the respective shaft 50, 51 and the respective orifice 53a, 53b of the driving pulley 14, in order to exert an action 25 radial forcing allowing the transmission of torque between the shaft and the respective pulley; and a clamping member 59a, 59b comprising a tubular portion 60a, 60b capable of axially clamping the associated forcing rings 58a, 58b and a flanged portion 61a, 61b having first threaded pass-through holes 62a, 62b for the screwing of said said first clamping screws 55 and second through holes 63a, 63b for the insertion of said second clamping screws 57.

  In the mounting example illustrated in FIG. 7, the clamping member 59b of the second wedging device 29b is tightened on the driving pulley 14, by means of said second screws 57, so as to axially push the associated rings 58b forcing against an abutment surface, formed by a shoulder 64 of the pulley and thus block by interference the hub of the pulley 14. 5 The clamping member 59a of the first wedging device 29a is on the other hand tightened on the pulley d attack 14 by means of said first screws 57, inserted on the axially opposite side in the respective holes 54 of the pulley and screwed into the holes 61a of said clamping member.

  Obviously, although an exemplary embodiment has been illustrated in which the driving pulley 14 has cylindrical orifices of different diameter and in which it is wedged on shafts 50, 51 of different diameters 15, it is in any case possible to provide a pulley having two orifices of the same diameter and to play on the choice of timing devices to allow the timing of the pulley on shafts of different diameters.

  Naturally, while maintaining the principle of the invention, the embodiments and the details of embodiment may be amply modified compared to what has been described and illustrated, by way of non-limiting example, without departing from the scope of the invention. scope of the invention, as defined in the appended claims.

Claims (13)

  1. Driving head (10) for a linear guide device comprising a beam (11) provided with guide means, oriented in the direction of the longitudinal axis of the beam (11), sliding means capable of sliding the along said guide systems and a transmission unit capable of moving said sliding means along the guide means, where said transmission unit comprises a belt member (12) intended to move said sliding means, a driving pulley (14) able to drive said belt member (12) and a motor unit (65) capable of driving the driving pulley (14) in rotation, the drive head (10) comprising an envelope intended to be fixed to one end of the beam (11) and to receive the driving pulley (14) with respective support elements (13a, 13b), characterized in that said envelope comprises two symmetrical halves (16a, 16b) , both compared to a pr first plane perpendicular to the axis of rotation of the driving pulley (14) as compared to a second plane perpendicular to the first and passing through the axis of rotation of the pulley (14), said halves 25 being fixed to the one to the other in order to form a body in which the drive pulley (14) and the support elements (13a, 13b) are received; and two outer plates (17a, 17b), or flanges, each fixed to one of said halves (16a, 16b), so as to close the body of the head (10) by parts axially opposite with respect to the pulley attack (14).   2. Driving head according to claim 1, characterized in that the flanges (17a, 17b) are formed of parts symmetrical with respect to said planes of symmetry of the two halves (16a, 16b); 3. Driving head according to claim 1 or 2, 5 characterized in that said halves (16a, 16b) are parts produced by extrusion in the direction of the axis of rotation of the driving pulley (14).   4. Driving head according to any one of the preceding claims, characterized in that the two halves (16a, 16b) and the two flanges (17a, 17b) are maintained in the assembled state by means of fastening members. screws (18a, 18b, 20).   5. Driving head according to claim 4, characterized in that the two halves (16a, 16b) are fixed to each other by means of pairs of screws (18a, 18b) inserted in respective pairs of axially opposite through holes (19a, 19b) and screwed by axially opposite parts in respective sockets (20) locked in respective cylindrical housings (21) formed partly of one half (16a) and partly of the other half (16b).   6. Driving head according to claim 5, characterized in that the two flanges (17a, 17b) are fixed to the respective halves (16a, 16b) by means of said screws (18a, 18b) which serve for the reciprocal fixing of the two halves ( 16a, 16b). 30 7. Drive head according to any one of the preceding claims, characterized in that each of the two halves (16a, 16b) has a first axially outer cylindrical housing (22a, 22b), for the respective support element (13a, 13b) and a second axially internal cylindrical housing (23a, 23b) for the driving pulley (14).   8. Driving head according to any one of the preceding claims, characterized in that at least one of the two flanges (17a, 17b) is provided with fixing systems (15) for the power unit (65) and / or for a transducer for reading the position / angular speed of the driving pulley (14).   9. Driving head according to any one of the preceding claims, characterized in that at least one of the two flanges (17a, 17b) has a central opening (28) for a shaft (50,51) on which 15 is wedged the attack pulley (14).   10. Driving head according to any one of the preceding claims, characterized in that the driving pulley (14) has a pair of coaxial cylindrical internal cavities (41 ', 41' ', 53a, 53b) capable of each accommodating a respective wedging device (29, 29a, 29b), so that the pulley (14) can be wedged simultaneously on two shafts (50, 51).   11. Driving head according to claim 10, characterized in that said coaxial cylindrical internal cavities (41 ', 41' ', 53a, 53b) have different diameters to accommodate wedging devices (29, 29a, 29b) suitable for wedging on different shaft diameters.   12. Driving head according to claim 10 or 11, characterized in that it comprises at least one wedging device (29) with two conical elements (30, 35 31) and in that the driving pulley (14) has a plurality of holes (42) for corresponding clamping screws (32) capable of clamping one on the other the two conical elements (30, 31) of said wedging device (29).   13. Driving head according to claim 10 or 11, characterized in that it comprises at least one wedging device (29a, 29b) comprising: at least one forcing ring (58a, 58b) inserted in an annular housing defined between a respective shaft (50, 51) and the respective cylindrical cavity (53a, 53b) of the driving pulley (14); a clamping member (59a, 59b) clamped against a respective axial face of the driving pulley (14) for axially forcing said forcing ring (58a, 58b) into the respective annular housing; and the screw connection members (56a, 56b, 52) for axially clamping said clamping member (59a, 59b) on the driving pulley (14).