KR20050086957A - Flexible flywheel for torque transmission device - Google Patents

Abstract

The invention concerns a flexible flywheel for torque transmission device, in particular for a motor vehicle, comprising a radially internal annular element (26) including means for being fixed on an input shaft and linked through at least two diametrically opposite radial arms (28) to an annular mass (30), the radial arms (28) defining an oscillation axis (34) for the flywheel perpendicular to the axis of rotation and which has a predetermined angular position relative to the input shaft.

Description

Flexible flywheel for torque transmission device {FLEXIBLE FLYWHEEL FOR TORQUE TRANSMISSION DEVICE}

The present invention relates in particular to a flexible flywheel for a torque transmission device for automobiles, the flexible flywheel being designed to be driven about an axis of rotation by a drive shaft, and having an annular mass with a flexible element designed to be fixed to the drive shaft. It includes.

In the case of automotive torque transmission devices, the drive shaft is the crankshaft of the internal combustion engine, and the torque is transmitted to a driven element, such as the input shaft of the gear transmission, for example, typically via at least one clutch and vibration damper.

In some embodiments, the flywheel is a first flywheel of a double-flywheel damper comprising a second flywheel centered and guided on the first flywheel via a bearing, and a vibration damper typically mounted between the two flywheels, The second flywheel forms a recoil plate of the clutch for transmitting torque to the input shaft of the transmission.

In the present state of the art, the annular mass of the flexible flywheel is usually formed by a cast iron ring gear fixed by screws or rivets to the radial outer periphery of the flexible annular sheet metal, the radially inner peripheral portion of the sheet metal being It comprises a hole for the passage of a screw for fixing it to the drive shaft, ie to the crankshaft of the internal combustion engine in the case of an automotive torque transmission device.

The flexible annular sheet metal has a relatively small thickness (for example about 2 to 3 mm), the radially inner circumferential part of which to fix it to the drive shaft is reinforced with a reinforcement washer having a larger thickness, and a set screw Can be supported thereon. This annular sheet metal of small thickness should be checked after cutting, reinforced if necessary and carefully assembled into the annular mass of cast iron. These operations are relatively long and complex and therefore expensive.

During operation, this type of flywheel is subjected to a "pumping" flexural deformation (a bending deformation in which the flexible flywheel remains essentially parallel to itself) and is perpendicular to the axis of rotation of the flywheel and on the crankshaft. Deformation by oscillations about an axis having an angular position defined relative to it is exerted, which is associated with the bending of the final crank pin of the crankshaft. Known flexible flywheels are characterized by a structure with rotational symmetry, and therefore do not need to consider this vibration phenomenon.

In particular, it is an object of the present invention to provide a flexible flywheel that meets these requirements and does not have the disadvantages of the flexible flywheel of the prior art.

Summary of the Invention

To this end, the invention relates to a flexible flywheel, in particular for a torque transmission device for automobiles, comprising an annular mass with a flexible element designed to be driven about a rotational axis by a drive shaft and fixed to the drive shaft. And a radial arm defining a good axis of oscillation perpendicular to the axis of rotation of the flywheel.

Thus, the flexible flywheel according to the invention is designed to respond in particular to the above-mentioned vibration phenomenon and to at least partially absorb the vibration phenomenon by separating the flywheel vibrating the good axis from the drive shaft.

Indeed, it may be advantageous for the radial arms of the flexible element to be formed with a locally increased thickness of this flexible element. That is, the flexible element has a thickness at that portion that forms the radial arm, which has a smaller thickness at that other portion, and this smaller thickness allows the flexible element to be reduced, even the radial arm It is omitted if it has sufficient thickness and rigidity to ensure transmission of torque between the drive shaft and the driven shaft.

Next, the flexible element of the flexible flywheel according to the present invention can be formed of thicker sheet metal of the prior art, which can be of lower quality and does not require any pretreatment, is easier to machine, and is deformed to a lesser extent. And not straightened, as a result of which the flywheel according to the invention can be manufactured at a lower cost than in the prior art.

It is also possible to produce flexible elements in one piece with annular masses, in particular they can be formed of cast iron of quality resistant to bending and torsional stresses, so that the annular mass and flexible elements can be manufactured separately and assembled with them. All related problems and disadvantages can be avoided.

According to another feature of the invention, the oscillation axis is basically formed by two radial arms or alternatively three radial arms, which extend into a continuum of each other between the rotational axis and the annular mass, of which two of the three radial arms Symmetric to one another with respect to the series of third radial arms, these three radial arms extend between the axis of rotation and the annular mass, respectively.

In the first embodiment, the flexible element is disc shaped and includes cutouts formed on both sides of the vibration axis.

All of these cuts may or may not pass through the passage.

If the flexible element is not formed in one piece with the annular mass, the flexible element is fixed to the annular mass with screws, rivets and the like at the ends of the radial arms described above.

The flexible element may be formed by a single element made of sheet metal of a desired thickness or by a number of plate elements superimposed with and fixed with the annular mass.

According to another feature of the invention, the flexible flywheel comprises hysteresis means which is provided with a flexible element and which cooperates in friction with the annular mass.

In one embodiment, these hysteresis means comprise two radial arms, the arms extending perpendicular to the oscillation axis, radially inner ends integral with the flexible element, and radially contacting the annular mass. It has an outer end.

The radial arm of the hysteresis means is formed in one piece with the flexible element, or alternatively forms part of a washer attached to the flexible element, which was designed to be fixed to the drive shaft together with the flexible element.

In another embodiment, the hysteresis means comprises two tabs integral with the flexible element and spring pins mounted in the semi-cylindrical housing of the two tabs integral with the annular mass, which tabs are perpendicular to the aforementioned vibration axis. Extend in the phosphorus direction.

According to another feature of the invention, the radial arm defining the oscillation axis comprises a cutout or notch for positioning the maximum stress between its radially inner end and the radially outer end.

This makes it possible to move the maximum stress away from the zone where the radial arm is fixed or connected to the annular mass.

The radial arms described above are inclined slightly obliquely from their radially inner ends with respect to the plane perpendicular to the axis of rotation in the direction opposite to the drive shaft.

According to another feature of the invention, the flexible element comprises means for defining a second oscillation axis perpendicular to the axis of rotation and to the oscillation axis described above.

The two vibration axes are defined by the radial arms of the flexible element.

In one particular embodiment of the invention, these radial arms have lugs having different strengths depending on whether they connect a radial arm defining the first oscillation axis or a radial arm defining the second oscillation axis to the annular mass. Is connected to the annular mass.

In particular the flexible flywheel according to the invention forms a first flywheel of a double-flywheel damper which also comprises a second flywheel designed to be connected to the input shaft of the transmission by a clutch and a vibration damper mounted between the two flywheels.

In one embodiment of the invention, the vibration damper is in the form of a spring oriented radially with respect to the axis of rotation in the stationary position of the double-flywheel damper.

Advantageously, the hysteresis means associated with the flexible first flywheel comprises a spring washer, which was supported by the flexible element of the first flywheel, supported by the first flywheel, or otherwise flexible of the first flywheel. It is mounted between the element and the annular mass supported by this flexible element.

The present invention may be better understood, and other features, details, and advantages of the present invention may be better understood when reading the following description, which is described by way of example with reference to the accompanying drawings.

1 is a schematic front view of a flexible flywheel according to the present invention;

2 is a schematic view of an axial cross section of the flywheel of FIG.

3 and 4 are views of a variant embodiment of the flexible flywheel, similar to FIGS. 1 and 2;

5 and 6 are views similar to FIGS. 1 and 2 for another modified embodiment,

7 is a schematic representation of an axial cross section of another variant embodiment of a flexible flywheel,

8 is a schematic perspective view of the flywheel of FIG.

9 and 10 are views of another variation of the present invention, similar to FIGS. 1 and 2,

11 shows schematically the placement of a continuous flexible element in a strip of sheet metal before cutting;

12 is a schematic elevation view of another variant embodiment of a flexible flywheel;

FIG. 13 is a schematic perspective view of the flywheel of FIG. 12;

14 is a schematic front view of another variant embodiment of the flexible flywheel,

15 and 16 are schematic cross-sectional views taken along lines XV-XV and XVI-XVI of FIG. 14, respectively;

17 is a schematic front view of another modified embodiment of the flexible flywheel;

18 and 19 are schematic axial cross-sectional views in a plane perpendicular to the flywheel of FIG. 17;

20 is a schematic front view of another modified embodiment of the flexible flywheel,

21 is a partial axial schematic cross-sectional view showing the flywheel of FIG. 20 on a larger scale;

22 is a schematic front view of another modified embodiment of the flexible flywheel according to the present invention;

23 is a schematic axial sectional view of a double-flywheel damper according to the present invention;

24 is a schematic axial half view of a variant embodiment of the double-flywheel damper,

25 and 26 are schematic axial cross-sectional views of two different variants of a double-flywheel damper according to the invention,

FIG. 27 is a schematic view of the flywheel of FIG. 1 showing the positioning relative to the drive shaft. FIG.

1 and 2, a first embodiment of a flexible flywheel according to the present invention is schematically illustrated.

Such a flexible flywheel, indicated at 10, is designed to transmit torque between a drive shaft 12, which is a crankshaft of an internal combustion engine of a motor vehicle, and a driven shaft (not shown), the driven shaft being for example a gear. It is an input shaft of the transmission and is designed to be mounted in a rotationally fixed manner to the hub 14 of the vibration damper coaxial with the flywheel 10 and the drive shaft 12.

In a known method, the hub 14 of the vibration damper is connected by a clutch E of the flywheel 10, the radial face 16 of which is on the side opposite to the drive shaft 12. It forms a friction surface that is oriented and cooperates with the friction disk 18 of the clutch E.

The flywheel 10 according to the invention is fixed to the end of the drive shaft 12 by screws 20, which screw 20 is parallel to the rotation shaft 22 of the drive shaft 12 and the flywheel 10. Orientated and uniformly distributed in a circle about this axis 22.

The screw 20 is received in an orifice 24 of the radially inner annular portion 26 of the flywheel 10, which annular portion 26 is annular by two oppositely opposed radial arms 28. Connected to the mass 30, the annular mass 30 surrounds the annular portion 26, the outer cylindrical periphery of which has a tooth 32.

In this embodiment, the annular portion 26, the radial arm 28 and the annular mass 30 are formed of a single piece made of cast steel, for example soft cast iron, of a quality that can withstand bending stress.

The arm 28 is not exactly perpendicular to the axis of rotation 22 but rather slightly obliquely inclined and extends from the annular portion 26 toward the clutch. This can increase the axial stiffness of the flywheel, making it more resistant to clutching forces and increasing pumping times.

The radial arms 28 have width and thickness dimensions that enable the transmission of the maximum torque generated by the internal combustion engine of the motor vehicle.

The radial arm 28 also forms a vibrating axis 34 perpendicular to the axis of rotation 22, the angular position about which axis is determined relative to the drive shaft 12 and known by measurement or calculation. (The angular position of the flywheel 10 relative to the drive shaft 12 itself is constant and determined by suitable means at the time of assembly).

The annular portion 26 and the radial arm 28 of the flywheel form a flexible element that allows bending deformation of the flywheel, similar to the flexible annular sheet metal of the flexible flywheel of the prior art (annular mass 30 is Displaced parallel to itself).

In addition, the radial arm 28 of the flywheel 10 allows vibration of this flywheel about its axis 34, which is related to the bending of the final crank pin of the crankshaft forming the drive shaft 12. There is this.

The section of the radial arm 28 is determined such that, for example, this vibration phenomenon is allowed at the vibration frequency of the crankshaft corresponding to approximately 2700 to 4500 rpm.

In one embodiment of the invention, the friction diameter is 220 mm, the radial arm 28 has a substantially rectangular cross section with elliptical or rounded ends, and the flywheel has a ductile cast iron having a burst strength of approximately 500 MPa. The radial arm 28 has a width of 30 mm to 40 mm and a thickness of 6 mm to 10 mm. Radius 36 connecting the radial arm to the annular mass 30 is determined to reduce stress concentration, for example approximately 8 mm.

The damping action in ductile cast iron is approximately three to four times greater than the damping action of iron.

In the variant embodiment shown in FIGS. 3 and 4, the vibration axis 34 of the flywheel 10 is symmetrical with one another by the same radial arm 28 and with respect to the axis 34 as described above. It is formed by two different radial arms 40 extending essentially in a direction opposite to the direction of the radial arm 28 with respect to the axis of rotation 22, which radial arm 40 is radial in the example shown. It forms an angle of approximately 140 ° with the directional arm 28.

These two radial arms 40 are slightly easier to cast than a single arm 28 and can also reduce the problem of removing the mold.

Alternatively, the structure of the flywheel 10 shown in FIGS. 3 and 4 is the same as the structure of the flywheel of FIGS. 1 and 2.

In the embodiment of FIGS. 5 and 6, the flywheel 10 is of the type shown in FIGS. 1 and 2, and can damp the vibrations of the flywheel about an axis 34 formed by the radial arm 28. Related to hysteresis means.

These hysteresis means comprise, for example, an annular shaped spring washer 42 which is made of spring steel and designed to be fixed to the end of the drive shaft described above simultaneously with the radially inner annular portion 26 of the flywheel. To this end, the spring washer 42 comprises an orifice 44 that coincides with an orifice 24 formed in the annular portion 26 for the set screw 20 to pass through, the inner diameter of which is defined by the annular portion of the flywheel ( It is basically the same as the inner diameter of 26).

This spring washer 42 comprises two oppositely opposed radial arms 46 extending in a direction perpendicular to the oscillation axis 34, the radially outer end 48 of the arm 46 being the shaft. Bends parallel to, pressure may be applied to the inner cylindrical surface 50 of the annular mass 30.

Under this situation, all vibrations of the annular mass 30 during operation create friction on the folded end 48 of the arm of the spring washer 42 which is fixed to the radially inner annular portion 26 of the flywheel.

In one variant embodiment, the end 48 of the arm 46 extends through a small orifice formed in the web connecting the annular portion 26 to the annular mass 30.

In the embodiment of FIGS. 7 and 8, the flywheel 10 according to the invention comprises two independent elements fixed to each other: a flexible element 52 made of sheet steel and an annular mass 30 made of cast iron. ), The flexible element 52 has an annular shape as a whole, and its radial outer periphery is fixed to the mass 30 by screws 54, rivets, and the like.

The flexible element 52 has a radially inner annular portion 56 formed with an orifice 58 through which fixing screws for fastening the element 52 at the end of the drive shaft and an element 52 in the annular mass 30. Radially outer annular portion 60 comprising an orifice through which a set screw 54 for fastening) is passed, and two oppositely opposed radial arms 62 connecting the annular portions 56, 60 to each other. It includes.

Preferably, the flexible element 52 is basically formed as an annular washer in which two opposing cuts 64 in the shape of kidney beans are formed, the cuts being formed between the radial arms 64.

Typically, the flexible element 52 is made of sheet steel with a thickness significantly greater than the thickness of the steel sheet forming the flexible element of the flexible flywheel of the prior art, which thickness is for example approximately 5 mm. . This thickness reduces the risk of deformation of the sheet during its processing and facilitates and simplifies the manufacture of the flexible element 52.

As mentioned above, the vibration axis of the flywheel is defined by the radial axis of symmetry of the radial arm 62.

In the alternative embodiment of FIGS. 9 and 10, the flexible element 72 of the flywheel 10 according to the invention passes through an orifice 76 which passes through a set screw for securing the element 72 at the end of the drive shaft. Is essentially formed of two radial arms 78 of the type described above having an inner annular portion 74 comprising a and an radially extending portion 80 facing outwards defining a vibration axis of the flywheel; The part 80 forms a zone for fixing it to the annular mass 30, and includes an orifice for the purpose of passing the fixing screw 82, a rivet, or the like.

Notches or cutouts 84 are formed on the sides of the radial arm 78 to form zones for positioning the maximum stress and for moving this maximum stress from the orifice through which the screw 82 passes.

FIG. 11 is a continuous view of a flexible element similar to the element 52 of FIGS. 7 and 8, with the outer periphery 86 of the flexible element including a point 90 opposite to the notch 88. These points and notches allow the flexible elements 52 to fit partially into one another when they are formed into strips of sheet metal.

As shown in FIG. 11, the point 90 of one element 52 extends into a notch 88, such as the next element 52.

To save space and thus material, the point 90 of each flexible element 52 is itself formed by two curved notches 92 formed in the radially outer annular portion 60 of the flexible element. do.

12 and 13, the flexible element of the flywheel 10 according to the invention is of the same shape as the flexible element 72 of FIGS. 9 and 10, extending in a plane perpendicular to the axis of rotation and It is coupled with the hysteresis means by a cross-shaped elastic element 96 attached to the element 72. This elastic element 96 has two oppositely opposite radial arms 98 of the same shape as the radial arm 78 of the flexible element 72 and overlapping on the flexible element, and the radial arm ( Radial outer end 102 perpendicular to 98 and pressed against the radial face of mass 30 to effect damping by radial friction upon vibration of the flywheel about an axis formed by radial arms 78 and 98. And two other radial arms 100 with ().

The elastic element 96 is fastened to the annular mass 30 with the ends of its radial arm 98 via the set screw 82 of the flexible element 72, the radially inner annular portion being the flywheel of the drive shaft. Orifice 104 for passing a screw to secure it.

In this embodiment, the flexible element 72 may be formed from a stack of elongated plate elements made of thin sheet metal, and the elastic element 96 forms part of the stack.

In the embodiment of FIGS. 14-16, the flywheel 10 is made of a single piece, such as, for example, cast iron, the radially inner annular portion 26 of the opposite of similar to that of the embodiment of FIGS. 1 and 2. It is connected to the annular mass 30 by means of two radial arms 28 facing each other and an annular web 108 of relatively small thickness, the annular web 108 being an annular portion 26, an annular mass ( Occupies all space between 30 and the radial arm 28. Next, the flexible element of the flywheel is a ring with a locally increased thickness forming the radial arm 28.

In contrast, this flywheel has the same structure as that of FIGS. 1 and 2.

In the embodiment of FIGS. 17 and 19, the flexible flywheel 10 comprises an annular mass 30 made of cast iron and a flexible element of the type shown in FIGS. 9 and 10, which flexible element comprises It is formed from a stack of identical elements 72 made of thin sheet metal.

As in the embodiment of FIGS. 9 and 10, this flexible element is secured to the annular mass 30 by screws 82, rivets, etc. at the end 80 of its radial arm 78 forming the oscillation axis. have.

As shown more clearly in FIG. 19, a stack of identical elements 72 is formed of such an annular sheet metal fixed to annular mass 30 by fastening screws 82 for securing flexible element 72. Attached to 110, the periphery of this thin annular sheet metal 110 is supported relative to the radial face of the annular mass 30 and forms hysteresis means for damping the fixation and vibration of the flywheel.

The stacked elements 72 may have a greater different thickness at the middle of the stack than at the ends of the stack to balance the bending stress. In addition, the hardness of the stacked elements may be different.

In the embodiment of FIGS. 20 and 21, the flexible element 10 is made of a single piece and has an annular mass 30 by two oppositely opposite radial arms 28 as in the embodiment described above. Two radially inward annular portions 26 connected to and perpendicular to the oscillation axis 34 formed by the radial arms 28 and extending from the annular portions 26 towards the annular arms 30. Radial tabs 112. The annular mass 30 also includes two radial tabs 114 oriented from the inner cylindrical surface of the mass 30 toward the annular portion 26, which radial tabs 112, 114 Terminated in semi-cylindrical housings aligned in pairs and oriented towards each other, which houses means such as spring pins 116 that form hysteresis means for damping the vibration of the flywheel about axis 34. do. In general, the hysteresis means comprises an intermediate element mounted between the annular portion 26 and the annular mass 30 in a direction perpendicular to the axis 34.

In the embodiment of FIG. 22, the flexible flywheel 10 has a radially inner annular portion with an orifice 24 through which fastening means for fastening to a drive shaft is formed, and four radial arms 28 of the type described above. And the arms are oriented at 90 ° to each other, and their radially outer ends are connected to the annular mass 30 by elastically deformable lugs 120 and 122, the lugs 120, 122 extends in a plane perpendicular to the axis of rotation, with its ends fixed to the radial arm 28 and to the annular mass 30 by screws, rivets or the like.

In the illustrated embodiment, each lug 120, 122 is elongated in shape and extends in a direction that is essentially perpendicular to the radial arm 28 to which the lug is fixed.

The two vibration axes 34 and 124 of the flexible flywheel are formed to be perpendicular to the rotation axis and to be perpendicular to each other, one of these vibration axes corresponding to the above-described axis 34, and the other 124 to the axis 34. Right angle to).

The lugs 120 fixed to the radial arms 28 that form the vibration axis 124 are fixed to the radial arms 28 that form the vibration axis 34. It has less strength than strength. This makes it possible to have two oscillation frequencies about two perpendicular axes, each at a defined angular position with respect to the drive shaft.

Vibration about axis 34 is characterized by low intensity and hence low frequency, and vibration about axis 124 is characterized by greater intensity and hence higher frequency.

The same result can be obtained by providing different masses that produce different inertia on the two vibration axes 34, 124. If the mass located on one oscillation axis is larger, the oscillation frequency becomes smaller about an axis perpendicular to this oscillation axis.

Of course, these two means may be combined, i.e., the strength of the lugs 120, 122 and the mass located on the oscillation axis may be different.

In the embodiment of FIGS. 23 to 26, the flexible flywheel according to the invention forms part of the double-flywheel damper and forms the first flywheel of the double-flywheel damper.

In FIG. 23, the flexible first flywheel 10 includes a radially inner annular portion 26 that forms a hub, the hub having a radially inner annular shape of the flexible annular sheet metal 132 by rivets 130. The part is fixed and its radial outer circumference is fixed by axial clamping to an annular mass 30 formed by two cylindrical rings 134 and 136, one welded to the inside of the other, the annular The outer periphery of the sheet metal 132 is clamped between the axial end of the inner ring 134 and the end edge of the outer ring 136.

Hysteresis means are associated with this flexible annular sheet metal, and are formed by spring washers 138, the radial outer circumference of which is the radius of the annular sheet metal 132 between the rings 134, 136 as shown. Clamped to the circumferential outer circumference, the inner circumferential portion of the washer includes a radial tab 140 elastically attached to the flexible annular sheet metal 132.

The flexible first flywheel 10 is coupled with a second flywheel 142 which is centered and rotationally guided on the hub 26 by means of a soft bearing 144 and which is of a conventional type clutch. Form a recoil plate.

Vibration dampers 146 with circumferential springs are mounted between the two flywheels and connect them flyably with the possibility of angular displacement between the flywheels, absorbing vibrations and irregularities due to torque.

This vibration damper comprises an input element that is rotationally fixed to the first flywheel 10 and an output element that is rotationally fixed to the second flywheel 142 in a conventional manner, in which case the input element is connected to the spring washer 138. While fixed by rivet 148, the output element is fixed by rivet 150 to the second flywheel.

A torque limiter is formed between the rings 134, 136 of the annular mass 30 by the axial clamping mounting of the outer periphery of the annular sheet metal 132, which ensures that the transmitted torque is greater than a predetermined maximum value. The relative rotation of the annular sheet metal 132 relative to the spring washer 138.

In the variant embodiment shown in FIG. 24, which is a half view of the axial cross-section of the flexible first flywheel for a double-flywheel damper, the first flywheel 10 comprises a flexible annular sheet metal 152, which sheet metal. The radially inner portion of is fixed by screws 154 to the end of the drive shaft simultaneously with the cylindrical hub forming the inner annular portion 26 of the flexible flywheel, and the radially outer annular portion of this sheet metal 152 is The cast iron annular mass 30 is fixed by the rivet 156.

This annular mass 30 supports the sealing plate 158 on the ring gear and also on the opposite side of the drive shaft, which is fixed to the annular mass 30 by means of rivets 160. And an inner circumferential edge 162 disposed radially oriented and proximate to the flexible annular sheet metal 152.

The spring washer 164 is mounted between the flexible annular sheet metal 152 and the inner periphery 162 of the closure plate 158 and forms hysteresis means for damping the bending vibrations of the first flywheel 10.

In the alternative embodiment of FIGS. 25 and 26, the double-flywheel damper, shown in axial section, has two annular parts connected to each other by a flexible first flywheel 10 and a torque limiter 176 according to the invention. Cloud for centering and guiding rotation of a second flywheel 170 formed of 172, 174 and a second flywheel 170 on a cylindrical hub formed of a radially inner annular portion 26 of the first flywheel 10. A bearing 178 is mounted between the two flywheels and includes a vibration damper 18 in the form of a radial or with a radial spring.

In a known method, the spring 182 of this vibration damper is guided on a cylindrical rod 184 received in the cylindrical casing 186, which rod is annular of the first flywheel about an axis 188 parallel to the axis of rotation. Mounted on the mass 30 so as to pivot at its radially outer end, the radially inner end of the cylindrical rod 184 being an inner annular portion 174 of the second flywheel 170 by an axis 190 parallel to the axis of rotation. Mounted to pivot on

The annular mass 30 of the first flywheel comprises a block 192 made of cast iron, which is accommodated between the cylindrical casing 186 of the spring of the vibration damper, the top being essentially triangularly oriented towards the axis of rotation. The shape allows for angular displacement of the cylindrical casing about its axis 188 of the joint on the annular mass 30.

The mass of block 192 is distributed on two orthogonal oscillating axes 34, 124 as described with reference to FIG. 22.

Block 192 is secured to the metal plate 196 of the annular mass 30 of the first flywheel by rivets 194 simultaneously with the radially outer portion of the flexible annular sheet metal 132 of the first flywheel.

The spring washer 198 is mounted on the side of the first flywheel rotated toward the drive shaft, between the above-described edge 200 of the metal plate 196 and the sheet metal 132. This spring washer forms a means for damping the bending deformation of the first flywheel.

The embodiment shown in FIG. 26 differs from that of FIG. 25 only in the formation of the block 192 of the first flywheel, in which case the block is simultaneously with the radially outer peripheral portion of the flexible annular sheet metal 132. It consists of the axial laminated body of the sheet metal 202 fixed to the metal plate 196 of a flywheel by the above-mentioned rivet 194. As shown in FIG.

Alternatively, this structure is the same as described above with reference to FIG.

With reference to FIG. 27, a more detailed description of the positioning of the flexible flywheel according to the invention on the drive shaft is given.

Generally, drive shaft 12 is a crankshaft that includes at least one crank pin 1200, 1201 that may be connected to at least one connecting rod (not shown) associated with the location of the heat engine. The crank pin, also called first crank pin 1200, is adjacent to the flexible flywheel 10 according to the present invention. The crank pin 1200 defines a plane P together with the axis of rotation 22 of the drive shaft and the flexible flywheel 10.

As mentioned above, the oscillation axis 34 of the flexible flywheel 10 according to the invention is essentially perpendicular to the rotation axis 22 and is positioned at an angle with respect to the drive shaft 12. This angle position is determined between the plane P and the vibration axis 34 as described above, and has a positioning angle α therebetween.

The value of the positioning angle α is optimized to achieve a reduction in the stress of the drive shaft and / or the noise generated by the engine. The value of the positioning angle α is determined by measurement or calculation. This value is a function of the number of cylinders of the heat engine concerned and also the arrangement of the cylinders. This value is also a function of the phenomenon or phenomena requiring reduction (basically stress and noise). The value of the positioning angle α is measured in the direction of rotation R of the drive shaft from the plane P to the oscillation axis 34 of the flexible flywheel 10 according to the invention.

For example, if the oscillation axis 34 is close to the plane P (ie, the value of the positioning angle α is approximately equal to 90 °), this position will most likely reduce the stress on the crankshaft. Let's do it.

In a heat engine, the maximum pressure exerted on the piston head is such that when the crank pin supporting the piston forms an angle with a right angle direction of approximately 15 ° to 20 ° in the rotational direction, that is, an angle substantially greater than the so-called explosion angle. (An angle with a right angle direction taken by the crank pin at the time of explosion) is generated. The offset in the direction of rotation of the drive shaft of approximately 15 ° to 20 ° of the flexible flywheel 10 according to the invention can reduce noise.

Thus, the value of the positioning angle α may be between about 80 ° and about 120 °. This makes it possible to suppress or reverse the reduction in noise generated in relation to the reduction in stress. Advantageously, the value of the positioning angle α can be between approximately 90 ° and 110 °. Advantageously, the stress can be reduced in the value of the positioning angle [alpha] of approximately 90 [deg.], While the noise generated in the value of the positioning angle [alpha] of approximately 120 [deg.] Is reduced. The intermediate value of the positioning angle [alpha] can be employed such that the stress and the noise generated are reduced, as is the function of that described in this form.

Claims (29)

Flexible for torque transmission devices, in particular for automobiles, comprising an annular mass 30 which is designed to be driven about the axis of rotation 22 by a drive shaft 12 and is provided with a flexible element designed to be fixed to the drive shaft. In the flywheel, The flexible element is characterized in that it comprises a radial arm 28 defining a good oscillation axis 34 perpendicular to the rotational axis 22 of the flywheel. Flexible flywheel for torque transmission. The method of claim 1, The vibrating shaft 34 has a predetermined angular position with respect to the drive shaft 22, characterized in that Flexible flywheel for torque transmission. The method according to claim 1 or 2, Said radial arm 28 extends between said axis of rotation 22 and said annular mass 30. Flexible flywheel for torque transmission. The method according to any one of claims 1 to 3, Characterized in that the oscillating shaft 34 is formed between the rotary shaft and the annular mass 30, with two radial arms extending in series with each other. Flexible flywheel for torque transmission. The method according to any one of claims 1 to 3, Said oscillation axis 34 is formed of three radial arms 28, 40, two of which are symmetrical to one another with respect to the continuum of the third radial arms 28. Flexible flywheel for torque transmission. The method according to any one of claims 1 to 5, The flexible element is annular and includes cutouts 64 on both sides of the vibration axis. Flexible flywheel for torque transmission. The method of claim 6, The cutting portion 64 is characterized in that all passing through the passage Flexible flywheel for torque transmission. The method according to any one of claims 1 to 7, The flexible element is characterized in that it is made of a single piece with the annular mass 30 Flexible flywheel for torque transmission. The method according to any one of claims 1 to 8, Characterized in that the flexible element is cast iron Flexible flywheel for torque transmission. The method according to any one of claims 1 to 8, Characterized in that the flexible element is made of iron Flexible flywheel for torque transmission. The method of claim 10, The flexible element is a separate part and is fixed to the annular mass 30 by screws 54, 82, rivets, etc. at the ends of the radial arms described above. Flexible flywheel for torque transmission. The method of claim 10 or 11, The flexible element is characterized in that it is formed by a plurality of plate elements 72 which overlap with and are secured with the annular mass 30. Flexible flywheel for torque transmission. The method according to any one of claims 1 to 12, The radial arm 38, which forms the oscillation axis 34, is connected to its radially inner end to a central ring 26 comprising an orifice 24 through which fixing means for securing it to the drive shaft passes. Characterized by Flexible flywheel for torque transmission. The method according to any one of claims 1 to 13, Characterized in that the flexible element further comprises hysteresis means (42, 100, 102, 110) in friction with the annular mass (30). Flexible flywheel for torque transmission. The method of claim 14, The hysteresis means comprises two radial arms 42, which arms extend perpendicular to the oscillation axis 34 and are in contact with the annular mass 30, with a radially inner end integral with the flexible element. Characterized in that it has a radially outer end which is Flexible flywheel for torque transmission. The method of claim 15, Characterized in that the radial arms of the hysteresis means form part of the flexible element. Flexible flywheel for torque transmission. The method of claim 16, The flexible element 72 comprises a stack of flat elements, characterized in that the radial arm 100 of the hysteresis means is formed on one element 96 of this stack. Flexible flywheel for torque transmission. The method of claim 15, Characterized in that the radial arm of the hysteresis means forms part of the washer 42 attached to the flexible element. Flexible flywheel for torque transmission. The method of claim 18, The washer 42 is designed to secure the flexible element to the drive shaft. Flexible flywheel for torque transmission. The method of claim 14, Said hysteresis means is characterized in that it comprises an intermediate element mounted in a direction perpendicular to the good axis 34 between the annular mass 30 and the inner annular portion 26 of the flexible element. Flexible flywheel for torque transmission. The method of claim 14, The hysteresis means comprises two tabs 112 integral with the flexible element and a spring pin 116 mounted in a semi-cylindrical housing of the two tabs 144 integral with the annular mass 30, the tabs Is extended in a direction perpendicular to the oscillation axis 34 Flexible flywheel for torque transmission. The method according to any one of claims 1 to 21, A radial arm 78 defining the oscillation axis comprises a cutout or notch 84 for positioning the maximum stress between its radially inner and radially outer ends. Flexible flywheel for torque transmission. The method according to any one of claims 1 to 22, The radial arm 28 defining the oscillation axis is inclined slightly obliquely from its radially inner end with respect to a plane perpendicular to the axis of rotation in a direction opposite to the drive shaft. Flexible flywheel for torque transmission. The method according to any one of claims 1 to 23, The flexible element comprises means 28 defining a second oscillation axis 124 perpendicular to the axis of rotation 22 and to the good oscillation axis 34, wherein the second oscillation axis 124 is a good axis ( Characterized by having a greater strength than that of Flexible flywheel for torque transmission. The method of claim 24, Said two vibration axes 34, 124 are defined by the radial arms 28 of the flexible element. Flexible flywheel for torque transmission. The method of claim 25, The radial arm 28 is characterized in that it is connected to the annular mass 30 by lugs 120, 122. Flexible flywheel for torque transmission. The method of claim 26, Lug 120 connecting two aligned radial arms to annular mass 30 has a different strength greater than that of lug 122 connecting two other radial arms 28 to annular mass 30. Characterized by having Flexible flywheel for torque transmission. The method according to any one of claims 1 to 27, Characterized by forming a first flywheel of a double-flywheel damper, which also includes a second flywheel 142, 170 designed to be connected to an input shaft of transmission and vibration dampers 146, 180 mounted between two flywheels. Flexible flywheel for torque transmission. The method of claim 28, The vibration damper 180 is characterized in that it comprises a spring 182 that is radially oriented at rest Flexible flywheel for torque transmission.