FR2904074A1 - ELECTROMAGNETIC CLUTCH DEVICE WITH DOUBLE FRICTION CONE AND FIXED COILS, AND MULTI-OUTPUT MECHANICAL TRANSMISSION MECHANISM HAVING SUCH A CLUTCH DEVICE - Google Patents

Abstract

- The device comprises an input wheel (1), two output shafts (A, A ') coaxial opposite on either side of the input wheel (1). Each output shaft (A, A ') has an electromagnetic clutch. Each clutch comprises: - a movable plate (3), which is integral in rotation and free in translation on its output shaft (A), and which has a conical friction surface, - a magnetic circuit (5) comprising a part fixed (7), in which is housed the electromagnet coil (9), and a movable part (8) which communicates a translational movement to the movable clutch plate (3) to bring it into contact with friction with the input wheel (1) when the electromagnet coil (9) is powered. Clutch devices. Geared motors for the control of car accessories.

Description

ELECTROMAGNETIC CLUTCH DEVICE WITH DOUBLE FRICTION CONE AND

  FIXED COILS, AND MULTIPLE OUTPUT MECHANICAL TRANSMISSION MECHANISM HAVING SUCH A CLUTCH DEVICE.

  The present invention relates to an electromagnetic clutch device with double friction cone and fixed (electromagnet) coils. It also relates to a mechanical transmission mechanism for distributing a driving power input between several outputs, which comprises such a dual clutch device. A cone clutch is characterized by a tapered friction surface with an apex angle varying from 15 to 40 depending on the coefficient of mutual friction of the parts in contact. This shape makes it possible to obtain, with the aid of an axial force of limited value, a normal force on the friction surfaces, thus a torque having a considerable value. The female cone is generally integral with the driving shaft, and the male cone can slide axially on the driven shaft. A clutch device is double friction cone if it has two conical friction surfaces, generally symmetrical with respect to the driving shaft. According to the French patent application No. 2,323,917, on behalf of the company FACET Enterprises Inc., there is known an electromagnetic device with frustoconical friction surface, which comprises input means, coaxial output means to the means input and drive means of the output means, which transmit a torque between the input means and the output means. These drive means comprise an adjustable friction ring, an inner body disposed coaxially with said friction ring for rotation with it and directional biasing means causing said adjustable friction ring to engage the output means. In addition, electromagnetic means for operating the friction device, arranged with respect to the inner body so as to form a flux circuit, comprise a magnetic armature and means for adjusting this armature with respect to the inner body, a circuit of flux being formed between the armature and the inner body when the electromagnetic means is energized. This electromagnetic friction cone clutch device has the advantage of being self-adjusting and equipped with means for compensating the wear of the torque transmission parts.

According to French Patent Application No. 2 545 895, also in the name of FACET Enterprises Inc., there is known an electromagnetically controlled friction device for transmitting a torque which comprises an input member, an output member, and a mechanism for transmitting a torque between the two members. This mechanism comprises an annular friction lining, a spring system which urges the liner against the input member and an electromagnetic biasing means for selectively moving the liner 20 away from the input member. This mechanism further comprises an adjustable stop disposed between the input member and the lining, intended to limit the authorized displacement of the lining, and thus to limit the frictional torque between these members. The position of the stop can be adjusted automatically when the biasing member is not actuated and the input member rotates in a given direction. It is also a self-adjusting friction cone device in which means are provided to prevent undesirable rotation of certain internal members with respect to the friction ring. According to US Pat. No. 3,994,379, also in the name of FACET Enterprises Inc., there is known an electromagnetic clutch whose control means comprises an electromagnet coil, a drive plate, an armature which is coaxial with the input shaft and is threadably connected to an annular friction drive member. The armature 2904074 3 responds to the excitation of the electromagnet coil and the annular drive member can move and come into contact with the armature to drive the output shaft. The relative rotational movement between the armature and the annular drive member causes the latter to advance on the thread until the total engagement with the output shaft control means is reached. . A retarder disposed between the armature and the control plate maintains the relative position between the armature and the annular drive member. The retarder allows a relative rotational movement between the annular drive member and the armature in one direction, and prevents any relative movement between the armature and the annular drive member in opposite directions.

In this device of the prior art, it is a question of having a strong magnetic engagement force, whatever the wear of the annular friction drive member, the latter being the main member. mechanical torque transmission.

According to U.S. Patent No. 4,416,359, also to FACET Enterprises Inc., a friction cone clutch device is known for transmitting a torque from a input shaft to a control plate and, via a plurality of spherical elements, to an annular conical friction member, and subsequently to an output member. The spherical members are located in opposed conical bulges with respect to each other within the control plate and an annular flange which is rigidly attached to the annular conical friction member. The engagement forces of the clutch are increased by the eccentric effect of the spherical elements in the conical bulges. The control plate also has a flexible member which allows the plate to flex axially in order to minimize the play resulting from the engagement of the spherical balls in conical bulges. The armature is disposed perpendicular to the electromagnetic coil to allow a large axially directed flexible path to provide a large clutch engagement force. The annular friction member is connected to the frame by means of a thread. Any relative movement between the armature and the annular friction member is prevented by an axial retarder, regardless of the play of the threaded parts. It is also a question of compensating for the wear of the transmission members 10 of the mechanical torque. Accordingly, the electromagnetic clutch devices with conical friction surface and fixed or mobile electromagnet coil are well known in the prior art, and are designed according to constructions that make them more or less compact and insensitive wear of mechanical transmission parts. The object of the present invention is to improve such devices known from the prior art by providing a double friction cone electromagnetic clutch device and electromagnet coils fixed in rotation as well as in translation. It is another object of the present invention to provide a dual friction cone and fixed coil clutch device which is as compact as possible, particularly in the axial direction of the device. Another object of the present invention is to provide such a clutch device, which is rigid, robust, simple and reliable operation. Another object of the present invention is to provide such a clutch device, wherein the input drive wheel is guided over a reduced axial distance. Another object of the present invention is to provide such a clutch device, which comprises a reduced number of parts, these parts being the most standard possible, and to produce a device whose assembly, from its constituent parts. , be simple and fast.

It is also an object of the present invention to provide such a clutch device which is able to integrate optimally into a mechanical transmission mechanism comprising an electric actuator and a plurality of outlets between which is distributed the motive power. To achieve these aims, the present invention provides a novel electromagnetic clutch device with double friction cone and fixed coils, which has an input wheel through which the driving power is supplied, two coaxial output shafts and on ends opposite which the toothed wheel is rotatably mounted, each output shaft having an electromagnetic clutch for setting or unloading the input power transmission to said output, and each clutch comprising: a movable platen, which is integral in rotation and free in translation on its output shaft, and which has a conical friction surface intended to come into contact with a conical fiction surface of the input wheel in the clutch position, - a magnetic circuit comprising a fixed portion in rotation and in translation, in which is fixedly mounted the electromagnet coil and a movable portion in trans tion 25 under the effect of the electromagnetic force generated when the coil is energized, - said movable portion of the magnetic circuit communicating its translational movement to the movable clutch plate to bring it into frictional contact with the wheel of input to the clutch position in which the input wheel is rotatably connected to said output shaft. According to a preferred embodiment of the invention, the movable part of the magnetic circuit comprises a sleeve-shaped portion 35 which is mounted on the output shaft and which has a lateral face intended to come into translational contact with a side surface of the clutch mobile plate 2904074 6, to bring the latter into frictional contact with the input wheel in the clutch position. According to an advantageous embodiment of the invention, the two output shafts comprise a short bore 5 at their end opposite, in which a single cylindrical bar is housed to stiffen the device and reduce the guiding distance of the wheel. 'Entrance. According to a second preferred embodiment of the invention, the fixed part of the magnetic circuit is placed against the movable plate of the clutch, so as to produce an even more compact device. Preferably, the opposite ends of the one and the other output shaft have a housing of square section, so as to accommodate a flexible tube containing a square section cable. According to one embodiment of the invention, the movable platen is rotatably mounted on its output shaft by means of a spline transmission.

Alternatively, the movable platen is rotatably mounted on its output shaft by means of a keyed transmission. Preferably, the fixed magnetic circuit is surmounted by a ring, so as to allow its integration into a housing. Also preferably, there is provided a washer inserted at the contact between the output shaft and the housing, so as to avoid wear of the latter.

The invention also provides a novel multi-output mechanical transmission mechanism, and this new mechanism comprises: a first module consisting of a dual friction cone clutch device and fixed electromagnet coils, in accordance with FIG. one of the various embodiments of the invention outlined above in outline, a second module comprising an electric actuator and a unit clutch module, and a third module with two outputs with a single clutch.

Other objects, advantages and features of the invention will be apparent from the following description of a preferred, non-limiting embodiment of the object and scope of the present patent application, accompanied by drawings in which: FIG. 1A is a sectional view along the line IA IA of FIG. 1B of an embodiment of the electromagnetic clutch device with double friction cone according to the present invention, FIG. 1B is a front view of FIG. FIG. 1C is a perspective view of the device of FIGS. 1A and 1B; FIG. 2A is a sectional view of a first embodiment of the friction cone electromagnetic clutch device; FIG. FIG. 2B is an enlarged view of the central portion of the device of FIG. 2A, designated B in the drawing of FIG. 2A; FIG. 3A is a sectional view along line III; A - IIIA of the 3B, a second variant embodiment of the electromagnetic clutch device with double friction cone according to the present invention; FIG. 3B is a front view of the device of FIG. 3A; FIG. 3C is a view. In perspective of the device of FIGS. 3A and 3B, FIG. 4 is a schematic representation of a transmission mechanism in which the dual clutch device of the invention can be integrated. In the drawing of FIGS. 1A to 1C, there is shown a mechanical transmission mechanism with two power outputs, S1 and S2, intended for example to be integrated in a device with multiple outputs (more than two outputs). Such a device may be, for example, a motor-reducer for distributing a mechanical power between several outputs, each output (or some of them) comprising an electromagnetic clutch intended to establish or to undo, on command, the transmitting part or all of the motive power to this output.

The part referenced 1 is a toothed wheel which is permanently connected to another toothed wheel (not shown) connected to the output shaft of an engine (not shown). The toothed wheel 1 is mounted idly on the ends 2 and 2 'of the two output shafts A and A' coaxial and in the extension of one another. In the remainder of this text, only the part relating to the output A will be described, the part relating to the output A 'being, mutatis mutandis, identical and symmetrical to the part A. A movable clutch plate 3 is axially movable on part 4 of the output shaft. This part 4 is provided with grooves, so that the movable plate 3 is rotationally integral with the output shaft A. On another referenced portion 6 of the output shaft A is mounted free to rotate the mechanism of electromagnet of the electromagnetic clutch, of general reference 5. The electromagnet mechanism 5 comprises a part movable in translation 7 and a fixed part in translation 8. The two parts 7 and 8 of the electro mechanism magnet 5 forms the magnetic circuit of the electromagnetic clutch, and both are free to rotate on the output shaft. On the part 8 is fixed mounting the coil 9 of the magnetic circuit. Only the mobile part 7 of the magnetic circuit 35 is in contact with one of its annular lateral faces with the mobile plate 3.

When power is supplied to the coil 9 of the electromagnet or magnetic circuit 5, the mobile part 7 of the magnetic circuit is moved in translation and communicates its translational movement to the movable plate 3 of the clutch. . The movable plate 3 then comes into contact with the friction cone 10 of the toothed wheel 1, thus making the gear wheel 1 and the movable plate 3 of the clutch integral in rotation, and consequently making the toothed wheel 1 and the gear unit integral. output shaft A, 10 integral with the movable plate 3 by the effect of the splines of the portion 4. The output shaft A is in the engaged position. In the engaged position which is described above, the plate 3 of the clutch rotates, while the movable portion (in translation) 7 of the magnetic circuit does not rotate. A resistive torque is thus introduced, which results from the relative movement of two surfaces in contact, namely the annular lateral surfaces in contact with the movable plate 3 and the mobile part 7 of the magnetic circuit 5.

When the solenoid coil 9 is energized, the moving part 7 of the magnetic circuit clutch mobile 5 drives the plate 3, which then comes into contact with the input gear 1 before the air gap - designated x - zero.

With reference to the drawings of FIGS. 2A and 2B, a variant of the device of FIGS. 1A to 1C is described. The elements of FIGS. 2A and 2B, which are identical to those of FIGS. 1A to 1C, bear the same reference numerals.

As can be seen in more detail in the drawing of FIG. 2B, the facing ends of output shafts A and A 'each have a short bore, referenced 12 (shaft A), respectively 12' (shaft AT'). A cylindrical bar 13 is housed in the bores 12 and 12 'of the two output shafts A and A'. This bar 13 has a dual role: it allows, on the one hand, to stiffen the device and, on the other hand, to reduce the distance 2904074 guiding the toothed wheel 1, namely the distance referenced V in the drawing of Figure 2B. Note that in some cases of use, the centering bar 13 is useless. For example, the bar 13 5 proves useless if the half length of the bore of the toothed wheel 1 is greater than N times the diameter of the toothed wheel. Note also that the centering bar 13 may not be of circular section and, in this case, serve to permanently couple the two output axes A, A ', the bar can be mounted or dismantled on the basis of standard parts. Such a mode of operation is necessary if the mechanism of the invention is applied to the electrical slider adjustment of a seat, in which two opposite outputs of the electric actuator are required. As regards the constituent materials of the different elements of the mechanism, they are different according to the function of the elements. The parts that participate in the magnetic flux circuit, such as the parts 7, 8, of the magnetic circuit 5, are pieces of magnetic material, known per se, such as steel. Parts which have a mechanical guiding function and which do not participate in the magnetic field conduction can be made in a variety of materials, the choice of which is dictated by the mechanical stresses they must withstand. Finally, the parts which, by one of their surface, participate in the coupling by friction - therefore to the clutch stricto sensu - are made from materials making it possible to obtain the geometric characteristics and the coefficient of friction adapted, in a manner also known per se. Another variant of the present invention is described with reference to the drawings of FIGS. 3A to 3C.

In this variant, the gap or space, referenced i in the drawing of Figure 2A, between the fixed portion 8 of the magnetic circuit 5 and the movable clutch plate 3 2904074 11 is removed. In the present variant of FIGS. 3A to 3C, the fixed part 8 of the magnetic circuit 5 and the movable clutch plate 3 are partially interleaved. The operating principle is identical to that of the devices described with reference to FIGS. 1A to 1C and 2A to 2B. Thus, when the coil 9 of the electromagnet or magnetic circuit 5 is supplied with electric current, the mobile part 7 of the magnetic circuit is moved in translation and communicates its translational movement to the mobile plate 3 of the clutch. . The movable plate 3 then comes into contact with the friction cone 10 of the toothed wheel 1, thus making the gear wheel 1 and the movable plate 3 of the clutch integral in rotation, and consequently making the toothed wheel 1 and the gear unit integral. output shaft A, secured to the movable plate 3 by the effect of a key 14. The output shaft A is in the engaged position. For the transmission of the torque between the movable clutch plate 3 and the output shaft A, any means known per se for securing can be used, for example the splines of the embodiment of FIGS. 1A to 1C or 2A to 2B. However, the use of a key 14 is less expensive than a spline connection type solution. 15 (FIG. 3C) shows a square section orifice at the end of output shafts A and A '. Indeed, the end of each shaft is intended to accommodate a flexible tube containing a square section cable for transmitting the torque to a gearbox, when the device of the invention is, as indicated further, integrated into a mechanism that distributes a motive power between several outputs. Given a relatively large mechanical torque, which may be greater than 1 Nm, the material envisaged for the output shafts must withstand high stresses; for this reason, the output shafts may be, by way of example only, and without limitation of the subject of the invention, made of steel. In this case, and again for example only, to avoid a steel / steel contact between the output shaft A, respectively A ', and the cylindrical centering bar 13', the latter can be realized by For example, a polymeric material, preferably made of ABS material (acrylonitrile-butadiene-styrene acronym). More generally, the cylindrical centering bar 13 'can be made from any material that can withstand the mechanical stresses of resistance to the applied force, such as polymer material, aluminum, etc. A search is made for a combination of different materials constituting the output shafts and the centering bar, which makes it possible to obtain the least noisy pairs of friction possible. The centering bar 13 'could be omitted if one of the output axes A, A' integrates it directly into its machining plane. However, it will be noted that in such an alternative embodiment, there would be a greater diversity of component parts, therefore fewer standard parts.

With reference also to the drawings of FIGS. 3A to 3C, the fixed portion 8 of the magnetic circuit 5 is surmounted by a ring gear 16, intended to facilitate the integration of said fixed part into the housing of the device (not shown).

A washer 17 is inserted at the contact between the output shaft A and the housing (not shown) to prevent wear of the latter. As can be seen in the drawing of FIG. 3C, the washer 17 and the flange-shaped portion of the movable portion 7 of the magnetic circuit each have a cut-out 17a, respectively 7a, for the insertion of a key or analogous which immobilizes in rotation the washer, respectively the movable portion 7. There is shown in the drawing of Figure 4 a mechanical transmission mechanism comprising an electric actuator M, a plurality of outputs S1 to S5 between which is distributed the motive power developed by the actuator M and various clutches El, E2, E3 and E5, on the outputs S1, S2, S3 and S5, respectively. It is in such a transmission mechanism or geared motor that the double clutch device according to the present invention can be integrated. In the nonlimiting example of the subject of the invention, shown schematically in the drawing of FIG. 4, the mechanism comprises: a first module, referenced m1, double module, with two clutches E1 and E2 (for two outputs S1 and S2), similar to the clutch devices with double friction cone and fixed coils described above, - a second module, referenced m2, or motor module, which comprises the electric actuator M (electric motor, 15 by example) and a single clutch module E3 for an output S3, - a third module, referenced m3, with two outputs S4 and S5 with a single clutch E5. The third module may be, by way of non-limiting example of the object of the invention, a slide module for controlling the translational movement of a vehicle seat on its horizontal rails. The two outputs S4 and S5 control the same function of movement on the slideways, each linked to a reducer placed 25 at the guide rail on both sides of the seat. Therefore, a single clutch is required for the two outputs S4 and S5 of the slide module m3. Of course, the present invention is not limited to the embodiments described and shown above as examples; other embodiments may be devised by those skilled in the art without departing from the scope and scope of the present invention.

Claims (10)

  1. Electromagnetic clutch device with double friction cone and fixed coils, which comprises an input wheel (1) by which the driving power is supplied, two output shafts (A, A ') coaxial and on the ends ( 2, 2 ') with respect to which the toothed wheel (1) is rotatably mounted, each output shaft (A; A') having an electromagnetic clutch for setting or disconnecting the power transmission to the output shaft , characterized in that each clutch comprises: - a movable plate (3), which is mounted integral in rotation and free in translation on its output shaft (A), and which has a conical friction surface intended to come into contact with a conical friction surface (10) of the input wheel (1) in the clutch position, - a magnetic circuit (5) comprising a fixed part (8) in rotation and in translation, in which the coil is fixedly mounted. electromagnet (9) and a moving part (7) in translation under the effect of the electromagnetic force generated when the coil (9) is powered, - said movable part (7) of the magnetic circuit (5) communicating its translational movement to the movable clutch plate (3). ) to bring the latter into frictional contact with the input wheel (1) in the clutch position in which the input wheel (1) is rotationally secured to said output shaft (A).   2. Device according to claim 1, characterized in that said movable portion (7) of the magnetic circuit (5) comprises a sleeve-shaped portion, which is mounted on the output shaft (A) and which has a side face intended to come into translation contact with a lateral surface of the movable clutch plate (3), to bring the latter into frictional contact with the input wheel (1) in the clutch position. 2904074 15   3. Device according to any one of claims 1 and 2, characterized in that the two output shafts (A, A ') comprise an identical short bore (12, 12') at their end opposite, in which a bar 5 cylindrical (13) is housed to stiffen the device and reduce the guide distance (V) of the input wheel (1).   4. Device according to claim 1, characterized in that the fixed part (8) of the magnetic circuit (5) is placed against the moving plate of the clutch (3), so as to achieve a more compact device.   5. Device according to claim 1, characterized in that the opposite ends of the one and the other output shaft (A, A ') have a housing of square section (15), so as to receive a tube flexible containing a square section cable.   6. Device according to claim 1, characterized in that the movable clutch plate (3) is mounted to rotate with its output shaft (A) by means of a spline transmission.   7. Device according to claim 1, characterized in that the movable clutch plate (3) is mounted integral in rotation on its output shaft (A) by means of a key transmission (14). 25   8. Device according to any one of claims 1 and 4, characterized in that the fixed part (8) of the magnetic circuit (5) is surmounted by a ring (16), so as to allow its integration into a housing.   9. Device according to claim 1, characterized in that a washer (17) inserted at the level of the contact between the output shaft (A) and the housing is provided so as to avoid the wear of the latter. .   10. Mechanical transmission mechanism with several outputs, characterized in that it comprises: - a first module (ml) constituted by double friction cone clutch device and fixed electro-magnet coils, in accordance with FIG. any one of claims 1 to 9, - a second module (m2) having an electric actuator (M) and a unit clutch module, and 5 - a third module (m3) with two outputs (S4, S5) with a only clutch (E5).