FR2837634A1 - Combined disk brake and torque transmission coupling, uses braking disks and coupling disks, and has coupling formed by ramps that engage, and which when disengaged use balls between ramps to reduce friction - Google Patents

Abstract

The brake and coupling has braking disks (11,5,12) coupled to the motor shaft (1) and the case (2). The disks are coupled and decoupled by a mechanism which uses ramps formed on one disk (11) and central rings (6,13) to engage the disks. To avoid friction between the ramps when the drive is decoupled, balls are positioned between them.

Description

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The present invention relates to a brake device interposed between a motor and a load, composed of brake discs, a spring and means cooperating to move the brake discs against the action of the spring and to transmit a mechanical torque from the motor shaft to a receiving shaft when the motor shaft is driven.

The invention relates more particularly to a brake for a tubular motor for driving a roller shutter winding tube or the like.

Utility model IT-BO-92 U 000009 discloses a brake device arranged in the tube of the drive motor of the winding tube of a rolling shutter or the like between the motor and a reduction gear. The brake is in the "braked" position, blocking the rotation of the winding tube, when the motor shaft is stopped and goes into the "free" position, releasing the rotation of the winding tube, when the motor shaft is trained. This brake device also has the function of transmitting mechanical torque from the motor to the reduction gear.

The brake device comprises two brake discs arranged opposite, one of which is mounted in pivot connection on the motor shaft and terminated by a pinion engaging the reduction gear and has a cutout in which a pin housed in the motor shaft can move, and the other of which is fixed to the motor tube. The device also comprises a compression spring between a bearing carrying the motor shaft and the brake disc mounted in pivot connection on the motor shaft. When the engine is not powered, the action of the

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 spring on the disc mounted in pivot connection on the shaft, presses the discs one against the other. In this way, the discs being immobilized one against the other, the reduction gear input pinion is immobilized, and the roller shutter is consequently blocked. When the motor is supplied, the motor shaft rotates relative to the brake disks initially immobilized. This rotational movement relative to the brake disc mounted in pivot connection on the motor shaft will induce by the action of the pin on the cutout a movement of translation of the disc against the action of the spring causing the disbonding of the discs. The roller shutter is therefore released. The rotational movement of the shaft relative to the disc continues until the axial force exerted by the disc in reaction to the weight of the flap balances the spring force or, failing this, until the pin arrives at an obstacle at the end of the cutout, and a mechanical torque is then transmitted from the motor to the reduction gear and, consequently, an opening or closing movement of the shutter. In this mechanism, the friction between the pin and the ramp is significant. This drawback makes the brake device not very reactive.

The object of the invention is to provide a brake device which overcomes this drawback. In particular, the invention proposes to produce a brake device in which the friction between the mechanical parts cooperating to separate the discs when the engine starts are reduced.

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 The device according to the invention is characterized in that the means cooperating to separate the discs comprise elements rolling on complementary ramps arranged on a circle centered on the axis of the drive shaft on at least one of the discs linked to the drive shaft and on at least one auxiliary part interposed between the discs linked to the drive shaft.

The brake device preferably comprises three brake discs.

According to the embodiments, when the device comprises three discs, the disc secured to the receiving shaft is in pivot connection with the driving shaft, the other disc linked to the driving shaft is by a sliding pivot link, these two discs are in sliding connection with each other, between one of these discs and the auxiliary part is interposed an auxiliary disc which has ramps cooperating with the ramps of the auxiliary part and which is integral with the drive shaft and only the brake disc not being adjacent to the auxiliary disc has ramps cooperating with the ramps of the auxiliary part.

According to the embodiments, when the device comprises three discs, the disc integral with the receiving shaft is in sliding pivot connection with the driving shaft, the other disc linked to the driving shaft is by a pivoting connection, the two discs are in sliding connection with one another, between one of these discs

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 and the auxiliary part is inserted an auxiliary disc which has ramps cooperating with the ramps of the auxiliary part and which is in sliding connection on the motor shaft and only the brake disc not being adjacent to the auxiliary disc has ramps cooperating with the ramps of the auxiliary part which is in pivoting connection sliding on the motor shaft.

According to the embodiments, when the device comprises three discs, the disc secured to the receiving shaft is in pivoting connection sliding on the driving shaft, the other disc linked to the driving shaft is secured to the driving shaft and these two discs have ramps cooperating with the ramps of the auxiliary part which is in pivoting connection sliding on the motor shaft.

According to the embodiments, when the device comprises three discs, the disc secured to the receiving shaft is in pivot connection on the motor shaft, the other disc linked to the driving shaft is in sliding connection on the driving shaft and these two discs have ramps cooperating with the ramps of the auxiliary part.

According to the embodiments, when the device comprises three discs, the disc integral with the receiving shaft is linked to the motor shaft by a pivot link, the other disc linked to the motor shaft is by a pivot link sliding allowing the disc to translate up to a shoulder and the two discs

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 have ramps cooperating with the ramps of the auxiliary part in slide connection with the motor shaft.

According to the embodiments, at least one of the parts provided with ramps comprises thereon balls trapped in raceways.

The accompanying drawing shows, by way of example, four embodiments of the device according to the invention.

Figure 1 is a view developed in the "braked" position of the auxiliary part and neighboring parts having ramps.

Figure 2 is a view developed in the "free" position of the auxiliary part and neighboring parts having ramps, when the drive shaft is driven in a first direction of rotation.

Figure 3 is a view developed in the "free" position of the auxiliary part and neighboring parts having ramps, when the drive shaft is driven in a second direction of rotation.

Figure 4 is a view developed in the "free" position of the auxiliary part and neighboring parts having additional ramps and stops, when the motor shaft is driven in the second direction of rotation.

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FIG. 5 is a view developed in the "braked" position of the auxiliary part and of the neighboring parts having parallel ramps.

Figure 6 is a view developed in the "free" position of the auxiliary part and neighboring parts having parallel ramps, when the drive shaft is driven in a first direction of rotation.

Figure 7 is a view developed in the "free" position of the auxiliary part and neighboring parts having parallel ramps, when the drive shaft is driven in a second direction of rotation.

FIG. 8 is a view developed in the "free" position of the auxiliary part and of the neighboring parts having parallel ramps and additional stops, when the motor shaft is driven in a second direction of rotation.

FIG. 9 is a view developed in the "braked" position of the auxiliary part and of the neighboring parts having ramps and stops.

FIG. 10 is a view developed in the "free" position of the auxiliary part and of the neighboring parts having ramps and stops, when the motor shaft is driven in a first direction of rotation.

Figure 11 is a view developed in the "free" position of the auxiliary part and neighboring parts

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 having ramps and stops, when the motor shaft is driven in a second direction of rotation.

Figure 12 is a view developed in the "free" position of the auxiliary part and neighboring parts having additional ramps and stops, when the motor shaft is driven in a second direction of rotation.

FIG. 13 is a diagram in the "braked" position of the brake device according to a first embodiment.

Figure 14 is a sectional view, in the "braked" position of the brake device according to a first embodiment.

Figure 15 is a sectional view, in the "free" position of the brake device according to a first embodiment, when the motor shaft is driven in a first direction of rotation.

FIG. 16 is a diagram in the "free" position of the brake device according to a first embodiment, when the motor shaft is driven in a first direction of rotation.

FIG. 17 is a diagram in the "free" position of the brake device according to a first embodiment, when the motor shaft is driven in a second direction of rotation.

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Figure 18 is a sectional view, in the "free" position of the brake device according to a first embodiment, when the motor shaft is driven in a second direction of rotation.

Figure 19 is a sectional view, in the "braked" position of the brake device according to a second embodiment.

Figure 20 is a sectional view, in the "braked" position of the brake device according to a third embodiment.

Figure 21 is a sectional view, in the "braked" position of the brake device according to a fourth embodiment.

Figure 22 is a sectional view, in the "braked" position of the brake device according to a fifth embodiment.

Figure 23 is an exploded view of the device according to the first embodiment.

FIG. 24 is a view developed in the "braked" position of the auxiliary part and of the neighboring parts having stops.

Figure 25 is a sectional view of the device having a juxtaposition of seven brake discs.

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 Figure 26 is a sectional view of an embodiment of the raceways for trapping the balls.

Figure 27 is a partially cut developed view of a part having raceways for trapping the balls.

Figure 28 is a detail view, in section, of a raceway for trapping the balls.

In a first embodiment shown in FIGS. 13 to 18 and in FIG. 23, the brake device consists of three juxtaposed discs 11, 5, 12, brought back into position against each other by a compression spring 4. Two of these brake discs 11 and 12 are linked to a motor shaft 1, the third is linked to a casing 2 by a slide link. The disc 11 is linked to the motor shaft 1 by a sliding pivot link. The other disc 12 is pivotally connected to the drive shaft 1 and is integral with a receiving shaft 3 causing a load. The two discs 11 and 12 are in slide connection with one another.

Between the two discs 11 and 12 linked to the drive shaft 1, the brake device has an auxiliary disc 13 secured to the drive shaft 1. Between this auxiliary disc 13 and the disc 11, an auxiliary part 6 is inserted. This auxiliary part 6 is in pivoting connection sliding on the motor shaft 1. It has an annular zone which comprises a succession of three

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 ramps 63 and three stops 65 on each of its faces. The ramps 63, shown in Figures 1 to 4 and 9 to 12, are placed on either side of the auxiliary part 6 symmetrically. It should be noted that this symmetry is not necessary for the proper functioning of the device. These ramps 63 have slopes allowing them to cooperate with other ramps 63 of complementary shapes distributed over annular zones of the same diameter on the one hand the auxiliary disc 13 and on the other hand on the disc 11. These ramps 63 have raceways 62 receiving balls 61. The stops 65 present on the auxiliary part 6 cooperate with the ends 64 of the ramps of the brake disc 11 or of the auxiliary disc 13. These stops 65 have two functions. On the one hand, they make it possible to limit the axial displacements of the parts 11, 6 and 13 by limiting the rotational strokes of these parts between them in order to prevent the balls 61 from escaping from the raceways 62. On the other hand apart, they allow the disc 11 to be driven in rotation by the auxiliary part 6 or the auxiliary part 6 by the auxiliary disc 13. However, it should be noted that these stops 65 are not necessarily necessary for the operation of the device. Indeed, the function of limiting the axial displacements of the parts 11, 6 and 13 can be provided for example, by a shoulder on the motor shaft 1 and the drive function can be provided by the contact actions of the balls 61 on parts 11, 6 and 13.

When the shutter motor is powered, the motor shaft 1 is rotated as well as the

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 auxiliary disc 13. The discs 11.5, 12 are, in the "braked" position, pressed against each other. The auxiliary disc 13 driven in rotation, rotates relative to the auxiliary part 6. This relative movement causes the displacement of the balls 61 in their paths 62 and the displacement of the ramps 63 linked to the auxiliary part 6 on the ramps 63 linked to the auxiliary disc 13 if the motor shaft 1 rotates in a first direction as shown in FIGS. 2, 10, 17 and 18 and on the ramps 63 linked to the disc 11 if the motor shaft 1 rotates in the other direction as shown in FIGS. 3, 11, 15 and 16. This displacement of the ramps 63 one on the other is accompanied by an axial displacement against the action of the spring 4, of the auxiliary part 6 and of the disc 11, or according to the direction of rotation, of the single disc 11. The consequence of axial displacement is the appearance of a clearance between the brake discs 11, 5, 12.

When the drive shaft 1 rotates in a first direction, as shown in FIGS. 2, 10, 17 and 18, the auxiliary disc 13 creates, on the auxiliary part 6, by means of its ramps 63 forces including the orthoradial components are at the origin of its rotation training. The brake disc 11 is then driven in rotation by obstacle of the stops 65 of the intermediate piece 6 on the ends 64 of the ramps of the brake disc 11. When the drive shaft rotates in the other direction, as shown in FIGS. 3, 11, 15 and 16 the auxiliary disc 13 rotates the auxiliary part 6 by obstacle of the ends 64 of its ramps on the stops 65 of the

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 auxiliary part 6. The auxiliary part 6 creates, on the brake disc 11, via its ramps 63 forces whose orthoradial components are at the origin of its rotation drive. Thus, the brake disc 11 is rotated when the engine is powered. It transmits its rotational movement to the receiving shaft 3 attacking the load by means of axes 19 hooped in the disc 11 and sliding in bores 18 made in the disc 12.

When the motor is no longer supplied with power, the motor shaft 1 becomes free and the thrust of the compression spring 4 presses the brake discs 11, 5 and 12 against each other, causing a relative displacement of the ramps 63. The device brake is then in the "braked" position. The discs 11, 5.12 pressed against each other prohibit the rotation of the load and therefore the movement of the shutter.

The stops 65 necessary for the rotary drive of the disc 11 by the auxiliary piece 6 or of the auxiliary piece 6 by the auxiliary disc 13 can also be arranged on the auxiliary piece 6 and on the auxiliary disc 13 as shown in FIGS. 9 to 11 or on the brake disc 11 and on the auxiliary disc 13 as shown in FIG. 24. Additional stops 66 shown in FIGS. 4 and 12 can be made on the brake disc 11 and on the auxiliary disc 13 to cooperate with those made on the auxiliary part 6. Like the stops 65, the additional stops 66 have two functions. On the one hand, they limit the

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 axial displacements of the parts 11, 6 and 13 by limiting the rotational strokes of these parts with one another in order to prevent the balls 61 from escaping from the raceways 62. On the other hand, they allow the rotation of the disc 11 by the auxiliary part 6 or the auxiliary part 6 by the auxiliary disc 13. Thanks to these additional stops, the drive torque of the load by the motor is no longer the result of the orthoradial components of the forces of the ramps 63 on the balls 61, but mainly the result of the contact forces between the stops 65 and 66 or between the stops 65, 66 and the ends 64 of the ramps. The transmissible mechanical torque is then independent of the force exerted by the spring 4 and the shape of the ramps. The stiffness of the spring can then be chosen, keeping as the sole criterion the braking torque necessary for immobilizing the roller shutter. However, it should be noted that these additional stops 66 are not necessarily necessary for the operation of the device.

Indeed, the function of limiting the axial displacements of the parts 11, 6 and 13 can be provided for example, by a shoulder on the motor shaft 1 and the drive function can be provided by the contact actions of the balls 61 on parts 11, 6 and 13.

A second embodiment shown in Figure 19 differs from the first in that the auxiliary disc 23 is in slide connection with the drive shaft 1, in that the brake disc 22 secured to the shaft

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 receiver 3 is in pivoting connection sliding on the motor shaft 1 and in that the disc 21 is in pivoting connection on the motor shaft. This architecture of the device makes it possible to accommodate the compression spring 4 in the receiving shaft 3, which gives the device a better compactness.

In a third embodiment shown in FIG. 20, the brake device consists of three juxtaposed discs 31, 5, 32, brought back into position against each other by a compression spring 4. Two of these brake discs 31 , 32 are linked to the motor shaft 1, the third disc 5 is linked to the casing 2 by a slide link. The disc 31 is secured to the drive shaft 1. The disc 32 is in pivoting connection sliding on the drive shaft 1 and is secured to the receiver shaft 3 driving the load.

The compression spring 4 bears on the disc 32 and on a stop on the motor shaft 1. Between the two discs linked to the motor shaft, an auxiliary part 6 is inserted. This auxiliary part 6 is in pivoting connection sliding on the motor shaft 1. This auxiliary part 6 is identical to that described in the previous embodiments. The two brake discs 31, 32 have ramps 63 cooperating with the ramps 63 of the auxiliary part 6.

When the engine is powered, the drive shaft 1 and the brake disc 31 are rotated.

When the motor shaft 1 rotates in a first direction of rotation, the ramps 63 of the brake disc 31 move on the ramps 63 of the auxiliary part 6 in

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 pushing it back axially. This auxiliary part 6 in fact pushes the brake disc 32 against the action of the compression spring 4. The device is then in the "free" position, the discs 31, 5.32 no longer being pressed against each other. . The engine torque is transmitted from the disc 31 to the receiving shaft 3 secured to the brake disc 32 via the auxiliary part 6.

When the drive shaft rotates in the other direction of rotation, the ramps 63 of the auxiliary part 6 move on the ramps 63 of the brake disc 32 by pushing it against the action of the spring 4. The device is then in position "free". The engine torque is transmitted from the disc 31 to the receiving shaft 3 secured to the brake disc 32 via the auxiliary part 6.

A fourth embodiment shown in FIG. 21 differs from the third in that the brake disc 41 is linked to the motor shaft 1 by a sliding link and in that the disc 42 is linked to the motor shaft 1 by a pivot link.

In a fifth embodiment shown in FIG. 22, the brake device has a brake disc 51 in pivoting connection on the motor shaft 1 allowing it to translate up to a shoulder 53 and a brake disc 52 in pivot connection on the motor shaft 1. The third brake disc 5 is as seen in the previous embodiments in slide connection with the casing 2. Between the two brake discs 51 and 52, is, in slide connection on the motor shaft 1, an auxiliary part 7

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 shown in Figures 5 to 8, comprising a succession of ramps 63 and stops 65 on an annular area. The ramps 63 located on either side of the part 7 are parallel to each other. They cooperate with ramps 63 arranged on annular zones on the brake discs 51, 52. These ramps 63 are provided with raceways 62 receiving balls 61.

When the shutter motor is powered, the motor shaft 1 is rotated as well as the auxiliary part 7. The discs 51, 5, 52 are, in the "braked" position, pressed against each other.

The auxiliary part 7 rotated, rotates relative to the discs 51.52. This relative movement causes the displacement of the balls 61 in their paths 62 and the displacement of the ramps 63 linked to the auxiliary part 7 on the ramps 63 linked to the disc 52 if the motor shaft 1 rotates in a first direction as shown in FIG. 6 and on the ramps 63 linked to the disc 51 if the drive shaft 1 rotates in the other direction as shown in FIG. 7. This displacement of the ramps 63 on each other is accompanied by an axial displacement against the action of the spring 4, of the auxiliary part 7 and of the disc 51 or according to the direction of rotation of the single disc 51. The consequence of axial displacement is the appearance of a play between the brake discs 51, 5, 52.

When the drive shaft 1 rotates in a first direction, as shown in FIG. 6, the auxiliary part 7 is pushed back due to its rotation relative to the disc 52 and pushes the disc 51 until it

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 comes into contact with the shoulder 53. The auxiliary part 7 then creates on the disc 52 by means of its ramps 63 forces whose orthoradial components are at the origin of the drive of the disc 52 in rotation. When the drive shaft rotates in the other direction, as shown in FIG. 7, the auxiliary part 7 pushes the disc 51 and drives the disc 52 in rotation by obstacle stops 65 on the ends of the ramps 64 of the disc 52.

When the engine is no longer powered, the drive shaft 1 becomes free and the thrust of the compression spring 4 presses the brake discs 51, 5 and 52 against each other causing a relative displacement of the ramps 63. The device brake is then in the "braked" position. The discs 51.5, 52 pressed against each other prohibit the rotation of the load and therefore the movement of the shutter.

The stops 65 necessary for the rotary drive of the disc 51 by the auxiliary part 7 or of the disc 52 by the auxiliary part 7 can also be arranged on the brake disc 51 and on the brake disc 52.

Additional stops 66 shown in FIG. 8 can be made on the brake discs 51 and 52 to cooperate with those made on the auxiliary part 7 and thus carry out an obstacle drive of the various elements 51,7, 52. Thanks to these stops additional, the load drive torque by the motor is no longer the result of the orthoradial components of the forces of the ramps 63 on the balls 61, but mainly the result of the

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 contact forces between the stops 65 and 66 or between the stops 65, 66 and the ends 64 of the ramps. The transmissible mechanical torque is then independent of the force exerted by the spring 4 and the shape of the ramps. The stiffness of the spring can then be chosen, keeping as the sole criterion the braking torque necessary for immobilizing the roller shutter.

The ramps 63 may have raceways 84 in which the balls are trapped. This characteristic aims to facilitate the mounting of the device by integrating the balls 61 in the auxiliary part 6 or in the discs 11, 13 with which they form a sub-assembly. These raceways 84 represented in FIGS. 26 to 28 consist of a lower part 83 of section having the shape of a semicircle of diameter slightly greater than that of the balls and an upper part 82 consisting of two vertical walls connecting on the lower part 83. These paths 84 have a depth greater than the radii of the balls 61 and have in their upper part 82 lateral lips 81 facing each other having a distance between them slightly less than the diameter of the balls 61. the engagement of the balls 61 in the raceway 84, the lips 81 are elastically deformed. The balls being trapped, the device does not require any auxiliary parts such as a cage, or grease which could move and disturb the operation of the brake. Such raceways 84 can be made indifferently

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 on the auxiliary part, on the auxiliary disc or on one of the brake discs. When such raceways 84 are produced on a part, the raceway on the vis-à-vis part can be summed up on a flat surface as shown in FIG. 26.

The invention can be applied to brake devices having a juxtaposition of more than three discs. For example, one can realize, as shown in FIG. 25, an embodiment of the device derived from the first embodiment. This device has a juxtaposition of seven brake discs. The brake discs 71, 72, 74 and 76 linked to the motor shaft are in slide connection with one another and the discs 73, 75 and 77 are in slide link with the casing 2.

In the embodiments described above, the brake discs, the auxiliary parts and the auxiliary discs fitted with ramps all have a succession of three ramps. However, it is also possible to carry out the invention using any number of ramps.

The brake device according to the invention is of course applicable to any system comprising a motor driving a load.

Claims (1)

1. Brake device interposed between an engine comprising a drive shaft and a load, comprising brake discs (11, 5.12; 21.5, 22; 31, 5, 32; 41, 5, 42; 51, 5 , 52) arranged opposite, elastic means (4) and cooperating means (61,62,63), when the motor shaft (1) of the motor is driven to spread the brake discs (11, 5, 12; 21, 5, 22; 31.5, 32; 41.5, 42; 51.5, 52) against the action of elastic means (4) and for transmitting mechanical torque from the drive shaft ( 1) to a receiving shaft (3) integral in rotation with one of the brake discs in connection with the motor shaft (1), the receiving shaft (3) being kinematically linked to the load, comprising, in an odd number , a juxtaposition of disks alternately linked to the motor shaft (1) and to a casing (2) containing the motor, the disks at the ends (11,12; 21,22; 31,32; 41,42) of the juxtaposition being linked to the tree (1), at least one of them being linked to the ar bre (1) by a pivot link, the discs linked to the casing (2) being by slide links, characterized in that the means cooperating to separate the discs (11,5, 12; 21, 5, 22; 31, 5, 32; 41.5, 42; 51, 5, 52) comprise rolling elements (61) on complementary ramps (63) arranged on a circle centered on the axis of the motor shaft 1 on at least one of the disks linked to the motor shaft and on at least one piece <Desc / Clms Page number 21>  auxiliary (6; 7) interposed between the discs linked to the motor shaft (1). 2. Brake device according to claim 1, characterized in that it comprises three brake discs (11, 5, 12; 21.5, 22; 31.5, 32; 41.5, 42; 51.5, 52). 3. Brake device according to claim 2, characterized in that the disc (12) integral with the receiving shaft (3) is in pivot connection with the motor shaft (1), in that the other disc (11 ) linked to the motor shaft (1) is by a sliding pivot connection, in that these two discs are in sliding connection with one another, in that between one of these discs and the part an auxiliary disc (13) is inserted between the auxiliary disc (13) which has ramps (63) cooperating with the ramps (63) of the auxiliary part (6) and which is integral with the motor shaft (1) and in that only the brake disc (11) not being adjacent to the auxiliary disc (13) has ramps (63) cooperating with the ramps (63) of the auxiliary part (6). <Desc / Clms Page number 22> 4. Brake device according to claim 2, characterized in that the disc (22) integral with the receiving shaft (3) is in sliding pivot connection with the motor shaft (1), in that the other disc ( 21) linked to the motor shaft is by a pivot link, in that these two discs (21, 22) are in sliding connection with one another, in that between one of these discs ( 21,22) and the auxiliary part (6) is inserted an auxiliary disc (23) which has ramps (63) cooperating with the ramps (63) of the auxiliary part (6) and which is in slide connection on the shaft motor (1) and in that only the brake disc (21) not being adjacent to the intermediate piece (6) has ramps (63) cooperating with the ramps (63) of the auxiliary piece (6). 5. Brake device according to claim 2, characterized in that the disc (32) integral with the receiving shaft (3) is in pivoting connection sliding on the motor shaft (1), in that the other disc ( 31) linked to the motor shaft (1) is integral with the motor shaft (1) and in that these two discs (31,32) have ramps (63) cooperating with the ramps (63) of the auxiliary part (6) which is in pivoting connection sliding on the motor shaft (1). <Desc / Clms Page number 23> 6. Brake device according to claim 2, characterized in that the disc (42) integral with the receiving shaft (3) is in pivot connection on the motor shaft (1) and in that the other disc (41 ) linked to the motor shaft (1) is in sliding connection on the motor shaft (1) and in that these two discs (41, 42) have ramps (63) cooperating with the ramps (63) of the part auxiliary (6) which is pivotally sliding on the motor shaft (1). 7. Brake device according to claim 2, characterized in that the disc (52) integral with the receiving shaft (3) is connected to the motor shaft (1) by a pivot connection, in that the other disc (51) linked to the motor shaft (1) is by a sliding pivot link allowing the disc (51) to translate up to a shoulder (53), and in that these discs (51,52) have ramps (63) cooperating with the ramps (63) of the auxiliary part (7) in sliding connection with the motor shaft (1). 8. Device according to any one of the preceding claims, characterized in that at least one of the parts provided with ramps (63) comprises thereon, balls (61) trapped in raceways (84).