Torque transmitting apparatus

Abstract

A hydrokinetic torque converter with a built-in bypass clutch is provided with an arrangement which regulates the cooling of the clutch at a rate dependent upon the slip between the coaxial driving and driven parts of the clutch, and hence upon the quantity of generated friction heat. The cooling unit for the driving and/or driven part of the clutch can employ, for example, one or more pumps; a supply of a substance which changes its aggregate state from liquid to gaseous or from solid to flowable in response to heating, and vice versa in response to cooling; one or more porous washers in the path for the flow of hydraulic fluid between the customary plenum chambers provided in the housing of the torque converter to move a piston of the driven part of the clutch into and from frictional engagement with the housing; and/or a system of recesses, grooves, channels and/or other passages serving to convey fluid between the chambers at a rate which is higher or highest when the clutch operates with maximum slip. Such rate can decrease to zero when the torque converter is idle or the clutch is fully engaged to operate without slip.

What is claimed:  
     
         1 . A hydrokinetic torque converter, comprising: 
 a housing rotatable about a predetermined axis;    a pump rotatable by said housing about said axis;    a turbine rotatable in said housing about said axis by and relative to said pump;    means for rotating said housing;    an output element rotatable about said axis and arranged to receive torque from said turbine;    a fluid-operated bypass clutch disposed in said housing and arranged to transmit variable torque between said housing and arranged to transmit variable torque between said housing and said output element, said clutch including a driving component rotatable with said housing and a driven component rotatable with said output element and movable axially of said housing into and from frictional engagement—with and without slip—with said driving component;    means for moving said driven component, including first and second plenum chambers containing bodies of hydraulic fluid at variable pressure with the provision for fluid flow between said chambers through said clutch;    means for regulating the fluid flow between said chambers in dependency upon the magnitude of torque being transmitted by the clutch; and    wherein said clutch further comprises at least one friction lining borne by one of said components and frictionally engaging the other of said components and frictionally engaging the other of said components in the engaged condition of said clutch, said components and said friction linings having friction surfaces each of which engages another of said surfaces at least in the engaged condition of said clutch, said regulating means having recesses extending at least substantially racially of said axis and provided in at least one of said surfaces to establish at least a portion of said fluid flow in the engaged condition of said clutch.    
     
     
         2 . The torque converter of  claim 1 , wherein said recesses are provided in surface of at least one of said components.  
     
     
         3 . The torque converter of  claim 1 , wherein said recesses are embossed into said at least one surface.  
     
     
         4 . The torque converter of  claim 1 , wherein said recesses are defined by displaced material of that one of said components and said at least one friction lining which is provided with said at least one surface.  
     
     
         5 . The torque converter of  claim 1 , wherein said at least one friction lining is a washer having a predetermined width as measured radially of said axis, at least some of said recesses being provided in the surface of at least one of said components, being overlapped by said at least one friction lining, and having a length exceeding said predetermined width.  
     
     
         6 . The torque converter of  claim 1 , wherein said at least one surface is provided with an annular array of between about 10 and 400 recesses.  
     
     
         7 . The torque converter of  claim 6 , wherein said array includes between about 100 and 300 recesses.  
     
     
         8 . The torque converter of  claim 1 , wherein at least some of said recesses are elongated and have lengths of between 10 and 50 mm.  
     
     
         9 . The torque converter of  claim 8 , wherein said lengths are between about 10 and 30 min.  
     
     
         10 . The torque converter of  claim 1 , wherein at least some of said recesses have depths less than about 0.3 mm.  
     
     
         11 . The torque converter of  claim 10 , wherein said depths are below 0.15 mm.  
     
     
         12 . The torque converter of  claim 1 , wherein at least some of said recesses have widths of between about 0.2 and 20 mm.  
     
     
         13 . The torque converter of  claim 12 , wherein said widths are between about 0.5 and 1 mm.  
     
     
         14 . The torque converter of  claim 1 , wherein the ratio of the area taken up by said recesses to the area of the non-recessed portion of said at least one surface is between about 2:1 and 1:200.  
     
     
         15 . The torque converter of  claim 14 , wherein said ratio is between about 1:1 and 1:10.  
     
     
         16 . The torque converter of  claim 1 , wherein said at least one surface has edges bounding said recesses, at least some of said edges being at least substantially rounded.