Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
  • F16D3/50—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members
  • F16D3/64—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members comprising elastic elements arranged between substantially-radial walls of both coupling parts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D13/00—Friction clutches
  • F16D13/58—Details
  • F16D13/60—Clutching elements
  • F16D13/64—Clutch-plates; Clutch-lamellae
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D13/00—Friction clutches
  • F16D13/58—Details
  • F16D13/60—Clutching elements
  • F16D13/64—Clutch-plates; Clutch-lamellae
  • F16D2013/642—Clutch-plates; Clutch-lamellae with resilient attachment of frictions rings or linings to their supporting discs or plates for allowing limited axial displacement of these rings or linings

Definitions

• Friction device for a clutch in particular for a motor vehicle, and clutch comprising such a device
• the present invention discloses a friction device for a clutch, especially a motor vehicle, and a clutch comprising such a device.
• a clutch In a motor vehicle, a clutch, single or double type, is intended to couple rotating members driving and driven substantially aligned axes of rotation.
• the rotary driving member is coupled to the engine, more particularly to a crankshaft of the engine, and the driven member is coupled to a gearbox shaft.
• the clutch comprises at least one mechanism driven in rotation by the driving member, this mechanism being fixed on a flywheel secured to the crankshaft.
• the mechanism comprises a lid, a diaphragm and a pressure plate all rotatably connected with the driving member.
• the clutch further comprises a friction device comprising a friction disk rotatably connected to the driven member.
• the diaphragm encloses the friction disk between the pressure plate and a reaction plate integral with the lid in rotation.
• the reaction plate is formed by the flywheel.
• the friction disc has a generally rotational support, carrying first and second friction linings respectively arranged on first and second bearing surfaces of the support. These first and second bearing faces are axially offset, so as to generate an axial flexibility between the first and second friction linings.
• the axial offset of the first and second bearing faces also called progressivity, allows low amplitude axial displacement of the first and second gaskets relative to each other when the friction disk is sandwiched between the pressure plate and the pressure plate. reaction tray.
• the displacement of the first and second packings relative to each other is less than 1 mm, preferably between 0.5 and 0.7 mm. Clamping of the friction disk between the pressure plate and the reaction plate is controlled by a user of the motor vehicle by means of a foot pedal.
• the foot pedal is movable between a disengaged position, in which the friction disc is not clamped, and a clutch position, in which the friction disc is clamped.
• the displacement of the reaction plate relative to the pressure plate being related to the displacement of the control pedal, the progressiveness allows, during the clamping of the friction disc, a greater travel of the control pedal.
• the axial displacement of the first and second packings relative to one another, during the progressive tightening of the pressure disk causes an additional travel of the control pedal between the beginning and the end of the increase of the pressure. clamping force.
• a friction device for a clutch in particular a motor vehicle, of the type comprising:
• first and second friction lining substantially annular and coaxial, and a support of general shape of revolution comprising a hub extended radially by at least one peripheral blade delimited by two angular edges, the blade comprising a bearing face connected to the first lining and at least one free span face in contact with the second liner, the bound and free bearing faces being separated from each other by an axial blade recess, delimited by two fold lines.
• the axial blade recess formed in the support creates a spring effect between the first and second packings during their compression between the pressure and reaction plates. This spring effect ensures the progressive activation of the clutch.
• a clutch In order to increase the torque transmitted by the clutch, the clamping force applied by the pressure plate is generally increased. Furthermore, the friction linings being delimited by inner and outer spokes, a clutch generally comprises vibration damping means arranged on a radius smaller than the inner radius of the friction linings. Preferably, it will be chosen to increase the inner radius of the friction linings in order to accommodate damping means which are more bulky and therefore more effective. In this case, the surfaces of the friction linings decrease.
• the increase in the clamping force applied by the pressure plate and the reduction of the surfaces of the friction linings cause a significant increase in the pressure exerted on the linings, and therefore on the blade recess ensuring progressivity. Important stresses thus appear in certain parts of the blades of the support, in particular, the portions delimited by angular contours. These constraints induce greater fatigue work, faster wear, as well as risks of rupture.
• the object of the invention is notably to remedy this premature wear of a friction device of a clutch intended for the transmission of high torques.
• each angular edge comprises a concave portion delimiting the blade recess and portions of the bound and free span faces adjacent to this blade recess, the portion concave angular edge forming a concave curve which, at any point delimiting the blade recess, has a tangent forming an angle between 70 and 110 ° with the fold line closest to the point where the tangent is considered.
• a friction device according to the invention may further comprise one or more of the following features:
• any point of the concave curve defining the free span face has a tangent forming an angle between 70 and 110 ° with the fold line closest to the point where the tangent is considered;
• the concave portion of the angular edge delimiting the free span face extends between the portion of the angular edge defining the blade recess and a straight portion of the angular edge coinciding substantially with a radius of the support;
• the concave portion of the angular edge delimiting the bonded bearing surface extends between the portion of the angular edge delimiting the blade recess and a portion of the angular edge delimiting an axial hub recess connecting the hub to the blade;
• the hub recess is delimited by two fold lines, any point of the concave portion of the angular edge defining the bound bearing face having a tangent forming an angle between 70 and 110 ° with the fold line delimiting the blade or hub recess, the closest to the point where the tangent is considered;
• the concave portion of the angular edge also defines the hub recess and a portion of the hub adjacent to the hub recess; the free span face of the blade is delimited by the angular edge of the blade and by a circular peripheral edge adjacent to this angular edge of the blade;
• the blade recess is defined by two substantially parallel fold lines inclined relative to a median radius of the blade at an angle between 40 and 50 °;
• the blade comprises two free span faces delimited respectively by the two angular edges of the blade;
• the blade comprises a face of free span formed on a tongue extending in a slot of the blade interposed angularly between the two free bearing faces delimited respectively by the two angular edges of the blade;
• the hub is extended radially by at least two adjacent peripheral blades defined respectively by two adjacent angular edges interconnected by a concave hub edge; the hub is extended radially by several peripheral blades, the blades connected to the first lining alternating with the blades connected to the second lining;
• At least one annular friction lining is delimited by external and internal contours, such that the ratio of the diameter of the outer contour to the diameter of the inner contour is less than 1, 4, preferably less than 1, 35;
• the invention also relates to a clutch for a motor vehicle comprising a friction device as described above.
• FIG. 1 is an axial sectional view of a friction device according to an embodiment of the invention
• Figure 2 is a partial front view of a support of the friction device of Figure 1
• Figure 3 is a view similar to that of Figure 2 of a friction device holder according to an alternative embodiment.
• FIG. 1 shows a friction device 10 for a clutch, in particular a motor vehicle.
• the friction device 10 comprises a damper 12 for transmitting a torque of a driving member, such as a crankshaft of a motor vehicle engine, to a driven shaft, such as an input shaft a gearbox.
• a driving member such as a crankshaft of a motor vehicle engine
• the damper 12 is mounted between an input rotary element, such as a friction disc 14 which can be rotatably connected to the crankshaft, and a rotary output element, such as a cylindrical hub 16 can be rotatably connected to the gearbox input shaft.
• the clutch comprises at least one mechanism (not shown) rotated by the driving member, this mechanism being fixed on a flywheel secured to the crankshaft.
• the mechanism comprises a lid, a diaphragm and a pressure plate all rotatably connected with the driving member.
• the diaphragm encloses the friction disk 14 between the pressure plate and a reaction plate secured to rotate the lid.
• the damper 12 is intended to filter vibrations coming from the engine of the motor vehicle.
• the damper 12 comprises damping means 17, interposed between guide washers 18 and 20, rotatably connected to the friction disk 14 by means of rivets 22, and a web 24, connected in rotation to the hub 16.
• the friction disk 14 comprises a support 28 of generally circular shape, carrying first 30 and second 32 substantially annular and coaxial friction linings.
• the support 28, shown in greater detail in FIG. 2, comprises a hub 34 extended radially by peripheral blades 36.
• Each peripheral blade 36 is delimited by two angular edges 38A and 38B and a circular peripheral edge 42 adjacent the angular edges 38A and 38B. It will be noted that two adjacent angular edges 38A, 38B of two adjacent peripheral blades 36 are interconnected by a concave edge 43 of the hub 34.
• Each blade 36 comprises a bearing surface 44 connected to the first pad
• the support 28 comprises blades 36 connected to the first seal 30 alternating with the blades 36 connected to the second seal 32.
• the connecting means 45 are rivet attachment holes. Note that, in this case, a rivet head protrudes in the thickness of the friction lining 30, 32. As the lining 30, 32 wears out, its thickness decreases until, when the friction disk is clamped, the pressure plate (respectively reaction plate) comes into contact with the rivet head rather than with the gasket. The clutch can no longer function properly.
• the connecting means may alternatively be gluing means. In this case, a greater thickness of the friction lining 30, 32 must be worn before the clutch is no longer functioning properly.
• the two fold lines 52A, 54A (respectively 52B, 54B) delimiting the recess 5OA (respectively 50B) are substantially parallel and inclined relative to a median radius of the blade 36 by an angle of between 40 and 50 ° preferably 45 °.
• the blade 36 further comprises a third free-span face 55 formed on a tongue 56 extending in a slot 57 of the blade 36 interposed angularly between the two surfaces of free bearing surfaces 46A, 46B.
• the bounded bearing faces 44 and the third free-span face 55 are separated from each other by a recess 58.
• This recess 58 is delimited by two fold lines 59I and 59E.
• the shape of the blade 36 will be equated with the shape of the orthogonal projection of this blade 36 on a plane perpendicular to the axis of the friction disk 14, in particular the plane of FIG. 2.
• Each angular edge 38A, 38B comprises a concave portion 6OA, 6OB delimiting the recess 5OA, 5OB blade and delimiting portions of the bearing faces 44 and free 38A, 38B adjacent to this recess 5OA, 5OB blade.
• the concave portion 6OA, 6OB of the angular edge 38A, 38B forms a concave curve which, at any point delimiting the recess 5OA, 5OB blade, has a tangent forming an angle between 70 and 110 ° with the fold line 52A, 52B or 54A, 54B nearest the point where the tangent is considered.
• the concave portion 6OA, 6OB of the angular edge 38A, 38B delimiting the free span face 46A, 46B extends between the portion of the angular edge delimiting the recess 5OA, 5OB blade and a straight portion 62A, 62B edge angular substantially coinciding with a radius of the support 28. Any point of the concave curve defining the free span face 46A, 46B has a tangent forming an angle between 70 and 110 ° with the fold line 52A, 52B.
• the free-span face 46A, 46B has a rounded edge 63A, 63B between the part of the angular edge delimiting the recess 5OA, 5OB of the blade and the rectilinear portion 62A, 62B of the edge. angularly coinciding substantially with a radius of the support 28
• concave portion 6OA, 6OB delimiting the bound bearing face 44 extends between the portion of the angular edge 38A, 38B delimiting the blade recess.
• any point of the concave portion 6OA, 6OB of the angular edge 38A, 38B delimiting the bound bearing face 44 has a tangent forming an angle between
• the concave portion 6OA, 6OB of the angular edge 38A, 38B also delimits the hub recess 64A, 64B and a portion of the hub 34 adjacent to the hub recess 64A, 64B.
• This shape of the blade 36 is optimized so that the stresses in this blade 36 are distributed as well as possible, which effectively limits the risk of rupture of the blade 36 and increases the life of the friction device. Therefore, the active surfaces of the first and second friction liners can be reduced compared to those of conventional friction liners.
• each annular friction lining 30, 32 being delimited by radially outer and inner contours, it will be preferable to choose a ratio of the outside diameter to the inside contour diameter of less than 1.4, for example less than 1, 35.
• the blades 36 can accept a pressure greater than three bars. This makes it possible to increase the pressure force applied to each friction lining, a high pressure compensating for the small surface area of the friction linings.
• the clutch advantageously comprises a device (not shown) for compensating for the wear of the friction linings 30, 32.
• a wear-compensating device allows the diaphragm of the clutch has a position when clamping the friction disc 14 which is substantially independent of the wear of the friction liners 30, 32.
• the invention is particularly suitable for a clutch whose rotary member is driven linked in rotation to an input shaft of an automatic gearbox. Indeed, an automatic gearbox generally inducing a greater number of clutch actuation than a manual gearbox, it is advantageous that this clutch is less sensitive to wear, as is the case for a clutch according to the invention.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Mechanical Operated Clutches (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34949262

Family Applications (1)

Country Status (6)

Families Citing this family (2)

Citations (2)

• 2004
  • 2004-07-29 FR FR0451708A patent/FR2873774B1/fr not_active Expired - Fee Related
• 2005
  • 2005-07-27 BR BRPI0512384-4A patent/BRPI0512384A/pt not_active IP Right Cessation
  • 2005-07-27 WO PCT/FR2005/050625 patent/WO2006018584A1/fr active Application Filing
  • 2005-07-27 CN CNA200580021104XA patent/CN1973145A/zh active Pending
  • 2005-07-27 KR KR1020077002148A patent/KR20070034608A/ko not_active Application Discontinuation
  • 2005-07-27 DE DE112005001863T patent/DE112005001863T5/de not_active Withdrawn

Patent Citations (2)

Also Published As

Similar Documents

Legal Events