Torque transmitting and torsion damping apparatus for use in motor vehicles

Abstract

A torsion damping apparatus between the crankshaft of the engine and the input shaft of the change-speed transmission of a motor vehicle has two flywheels one of which is driven by the crankshaft and the other of which drives the input shaft by way of a friction clutch which generates heat. In order to prevent the transfer of heat from the friction clutch to the antifriction bearing between the flywheels, which are rotatable relative to each other against the opposition of a damper, the bearing is at least partially surrounded by a thermal barrier of synthetic plastic, ceramic or metallic material which prolongs the useful life of the bearing and enhances the torsion damping action of the damper. The thermal barrier can constitute or form part of the damper. The bearing can be disposed radially inwardly of the location of engagement between the clutch and the other flywheel and can be cooled by streams of air flowing through an annulus of passages each having a first end disposed radially inwardly of the friction surface of the other flywheel and a larger second end in a second surface of the other flywheel opposite the friction surface. Heat barriers in the other flywheel can alternate with the passages in the circumferential direction of the other flywheel.

We claim:  
     
       1. Apparatus for compensating for variations of torque, especially for fluctuations of torque which is transmitted between a combustion engine and an input means of a transmission, comprising at least two flywheels which are rotatable relative to each other, one of which is connectable with the engine and the other of which is connectable with the input means of the transmission and carries a disengageable friction clutch; antifriction bearing means interposed between said flywheels; a substantially disc-shaped member non-rotatably connected with said other flywheel; and damper means arranged to oppose rotation of said flywheels relative to each other, said damper means at least comprising energy storing means acting in the circumferential direction of said flywheels, and a friction generating device which is disposed between said flywheels, said friction generating device operating with friction axially between said member and said one flywheel and comprising a friction ring and a stressed energy storing element acting in the axial direction of said flywheels. 
     
     
       2. The apparatus of claim  1 , wherein the stressing of said energy storing element of said friction generating device is such that said energy storing element exerts a force having a component acting against said other flywheel in a direction at least substantially counter to the direction of action of force which is to be applied to disengage the friction clutch. 
     
     
       3. The apparatus of claim  1 , wherein said energy storing element reacts against said antifriction bearing means. 
     
     
       4. The apparatus of claim  1 , wherein said other flywheel has a shoulder and said antifriction bearing means is disposed between said shoulder and said member in a predetermined axial position relative to said flywheels. 
     
     
       5. The apparatus of claim  4 , wherein said antifriction baring means comprises an inner race and an outer race surrounding said inner race, and further comprising a thermal barrier between said antifriction bearing means and said other flywheel, said thermal barrier comprising heat-insulating rings each having a substantially L-shaped cross-sectional outline and each including an annular portion surrounding said outer race and a radially extending portion sealingly engaging said inner race. 
     
     
       6. The apparatus of claim  5 , wherein one of said heat-insulating rings is adjacent said member and another of said heat-insulating rings is adjacent said shoulder. 
     
     
       7. The apparatus of claim  1 , wherein said member includes a portion which is adjacent said antifriction bearing means and is disposed at a first radial distance from the axes of said flywheels, said friction generating device being disposed at a second radial distance from said axes and said second distance at least approximating said first distance, said friction generating device engaging said portion of said member. 
     
     
       8. The apparatus of claim  1 , wherein said one flywheel comprises an axial protuberance having an external shoulder and an end face, and further comprising a disc at said end face, said antifriction bearing means including a race disposed between said shoulder and said disc. 
     
     
       9. Apparatus for compensating for variations of torque, especially for fluctuations of torque which is transmitted between a combustion engine and an input means of a transmission, comprising: 
       
         at least two flywheels which are rotatable relative to each other about a predetermined axis, one of which is connectable with the engine and the other of which is connectable with the input means of the transmission by way of an engageable and disengageable friction clutch mounted on said other flywheel, said other flywheel having a shoulder;  
       
       
         damper means arranged to oppose rotation of said flywheels relative to each other, said damper means at least comprising energy storing means acting in a circumferential direction of said flywheels and being located at a first radial distance from said axis;  
       
       
         roller bearing means interposed between said flywheels;  
       
         a substantially disc - shaped member; and    
         means for preventing rotation of said member relative to said other flywheel, including a form - locking connection provided between said member and said other flywheel at a second radial distance from said axis less than said first radial distance, said bearing means being located between said shoulder and said member in a predetermined axial position relative to said other flywheel and said member having means for stressing said energy storing means in said circumferential direction in response to rotation of said flywheels relative to each other.    
     
     
       10. The apparatus of claim  9 , wherein said friction clutch is arranged to generate heat, and further comprising thermal insulator means between said other flywheel and said bearing means to oppose the transfer of heat from said friction clutch on said other flywheel to said bearing means.  
     
     
       11. The apparatus of claim  9 , further comprising a friction generating device disposed between said flywheels, operating with friction axially of said flywheels between said disc- shaped member and said one flywheel, and comprising a friction ring and a stressed energy storing element acting in the axial direction of said flywheels.    
     
     
       12. The apparatus of claim  11 , wherein the stressing of said energy storing element of said friction generating device is such that said energy storing element exerts a force having a component acting against said other flywheel in a direction at least substantially counter to the direction of action of force which is to be applied to disengage the friction clutch.  
     
     
       13. The apparatus of claim  11 , wherein said energy storing element of said friction generating device reacts against said bearing means.  
     
     
       14. The apparatus of claim  9 , wherein said bearing means comprises an inner race and an outer face surrounding said inner race, and further comprising a thermal barrier between said bearing means and said other flywheel, said thermal barrier comprising heat- insulating rings each having a substantially L - shaped cross - sectional outline and each including an annular portion surrounding said outer race and a second portion extending radially of said axis and sealingly engaging said inner race.    
     
     
       15. The apparatus of claim  14 , wherein one of said heat- insulating rings is adjacent said disc - shaped member and another of said heat - insulating rings is adjacent said shoulder of said other flywheel.    
     
     
       16. The apparatus of claim  9 , wherein said disc- shaped member includes a portion which is adjacent said bearing means and is disposed at a third radial distance from said axis, and further comprising a friction generating device disposed between said flywheels said flywheels at a fourth radial distance from said axis, said fourth distance at least approximating said third distance and said friction generating device engaging said portion of said member.    
     
     
       17. The apparatus of claim  9 , wherein said one flywheel comprises an axial protuberance having an external shoulder and an end face, and further comprising a disc at said end face, said bearing means including a race disposed between said external shoulder of said axial protuberance and said disc.  
     
     
       18. The apparatus of claim  9 , wherein said damper means comprises series- connected first and second dampers, said energy storing means forming part of at least one of said first and second dampers.    
     
     
       19. The apparatus of claim  9 , wherein said bearing means has an inner race and an outer race, said outer race being confined between said shoulder of said other flywheel and said disc- shaped member and said one flywheel having a second shoulder engaged by said inner race and provided on a protuberance of said one flywheel, said protuberance extending from an output element of the engine and further comprising a sheet metal member and fastener means securing said sheet metal member to said one flywheel, said sheet metal member including a radially outer portion and said inner race being secured between said radially outer portion of said sheet metal member and said second shoulder.    
     
     
       20. The apparatus of claim  9 , further comprising a thermal insulator having means for at least reducing the transfer of heat between said other flywheel and said bearing means, said means for at least reducing the transfer of heat comprising at least one insulating ring which is disposed between said substantially disc- shaped member and said shoulder of said other flywheel, said at least one insulating ring having a first section surrounding an outer race of said bearing means and at least one second section extending substantially radially inwardly of said first section toward an inner race of said bearing means.    
     
     
       21. The apparatus of claim  20 , wherein said at least one second section of said insulating ring includes a portion in sealing engagement with said inner race.  
     
     
       22. The apparatus of claim  20 , wherein said at least one second section of said insulating ring is resilient and bears against said inner race of said bearing means.  
     
     
       23. The apparatus of claim  20 , further comprising means for biasing said at least one second section of said insulating ring against said inner face of said bearing means, said biasing means comprising a diaphragm spring.  
     
     
       24. The apparatus of claim  20 , further comprising a seal between said thermal insulator and said outer race of said bearing means.  
     
     
       25. The apparatus of claim  9 , wherein said other flywheel has a friction surface cooperating with a clutch plate of said friction clutch, said other flywheel further having a side facing the engine and axially extending passages disposed radially intermediate said friction surface and said bearing means for streams of cooling air flowing from the clutch through said passages toward said side of said other flywheel and substantially radially outwardly through a space between said flywheels, and further comprising an insulator between said bearing means and said other flywheel.  
     
     
       26. The apparatus of claim  25 , wherein said damper means has at least one wall positioned to be contacted by cooling air.  
     
     
       27. The apparatus of claim  25 , wherein said passages are elongated in the circumferential direction of said other flywheel.  
     
     
       28. The apparatus of claim  25 , wherein said passages have slot- shaped portions at said friction surface and their cross - sectional areas increase toward said side of said other flywheel.    
     
     
       29. The apparatus of claim  25 , wherein said passages resemble passages of air circulating vanes.  
     
     
       30. The apparatus of claim  25 , wherein said passages are adjacent said bearing means.  
     
     
       31. The apparatus of claim  25 , wherein said passages include substantially radially outwardly extending recesses in said side of said other flywheel and extend along at least a portion of the width of said friction surface in the radial direction of said other flywheel.  
     
     
       32. The apparatus of claim  25 , wherein said other flywheel has internal surfaces surrounding said passages and at least one of said passages includes an inner portion nearer to said axis and an outer portion more distant from said axis, said inner portion extending from said friction surface in at least substantial parallelism with said axis and said outer portion diverging radially outwardly from said axis toward said side of said other flywheel.  
     
     
       33. The apparatus of claim  25 , wherein said passages are uniformly distributed about said axis.  
     
     
       34. The apparatus of claim  25 , wherein said passages from a circle around said axis and said circle has a center located at least close to said axis.  
     
     
       35. The apparatus of claim  25 , wherein said passages have a combined length, as seen in the circumferential direction of said other flywheel, which is between  20  and  70  percent of the total length of the corresponding portion of said other flywheel.  
     
     
       36. The apparatus of claim  25 , wherein said other flywheel has webs which alternate with said passages in the circumferential direction of said other flywheel, said passages having a first width in said circumferential direction and said webs having a second width between  0 . 5  and  2 . 5  times said first width.  
     
     
       37. The apparatus of claim  25 , wherein said damper means further comprises an output member including said disc- shaped member, and said form - locking connection includes fasteners alternating with said passages in the circumferential direction of said other flywheel.    
     
     
       38. The apparatus of claim  37 , wherein said damper means further comprises friction generating means.  
     
     
       39. The apparatus of claim  37 , wherein said fasteners alternate with pluralities of passages in the circumferential direction of said other flywheel.  
     
     
       40. The apparatus of claim  39 , wherein said other flywheel further comprises narrower first webs between the passages of said pluralities of passages and wider second webs connected to said fasteners.  
     
     
       41. The apparatus of claim  40 , wherein the width of each second web equals or approximates the combined width of two first webs.  
     
     
       42. The apparatus of claim  25 , wherein said insulator comprises means for at least impeding the transmission of heat from said friction surface to said bearing means, including at least one ring having a substantially L- shaped cross - sectional outline.    
     
     
       43. The apparatus of claim  42 , wherein said means comprises a first race and a second race, said at least one ring including a first portion extending along one of said races in the direction of said axis and a second portion extending along the other of said races substantially radially of said axis.  
     
     
       44. The apparatus of claim  43 , wherein at least one of said portions of said at least one ring sealingly engages the respective race.  
     
     
       45. The apparatus of claim  42 , wherein said insulator further comprises a diaphragm spring reacting against said other flywheel and bearing against said at least one ring to bias one of said portions of said at least one ring against the respective race.  
     
     
       46. The apparatus of claim  45 , wherein said diaphragm spring reacts against a radially outer portion of said other flywheel and bears axially against the second portion of said at least one ring.  
     
     
       47. The apparatus of claim  25 , wherein said flywheels include a first flywheel having an axial protuberance and a second flywheel having a centrally located recess for said protuberance, said bearing means surrounding said protuberance in said recess and said insulator being disposed in said recess between said bearing means and said second flywheel.  
     
     
       48. The apparatus of claim  25 , wherein said insulator constitutes the only means for sealing said bearing means.  
     
     
       49. The apparatus of claim  9 , wherein said friction clutch has a clutch plate engageable by a friction surface of said other flywheel, said bearing means including a first race and a second race and said other flywheel further having substantially axially extending air conveying passages disposed radially between said bearing means and said friction surface, and further comprising an insulator having means for at least impeding the transmission of heat including at least one ring having a substantially L- shaped cross - sectional outline and including a first portion extending along one of said races in the direction of said axis and a second portion extending along the other of said races substantially radially of said axis, said insulator further having a diaphragm spring reacting against a radially outer portion of said other flywheel and bearing against a radially inner portion of said second portion of said at least one ring in the direction of said axis to maintain said second portion of said at least one ring in sealing engagement with said other race.    
     
     
       50. The apparatus of claim  49 , wherein said other flywheel has a side confronting the engine and adjacent a wall of said damper means, said passages being elongated in the circumferential direction of said other flywheel and being configured to convey streams of cooling air from said friction clutch to said side of said other flywheel against said wall of said damper means and substantially radially outwardly through a space between said flywheels.