Torque-sensing locking differential with reduced parts

Abstract

A locking differential in which the two side gears comprise end toothings facing one another, and the differential component is a differential disc with end toothings on both faces, with the end toothings on each face co-operating with one of the side gears' end toothings. The number of teeth of each pair of inter-engaging end toothings differs by one, and the ratio of the number of teeth of both pairs of toothings is unequal. The differential disc is mounted to wobble between the side gears so that, by means of diametrically-opposed portions of its two sets of end toothings, it engages the associated sets of end toothings of the side gears. In a first embodiment, the desired ratios of the numbers of teeth exist if the differential disc is provided with end toothings with identical numbers of teeth (z=n), and one side gear comprises a set of end toothings having one tooth fewer (z=n−1) and the other side gear having one tooth more (z=n+1). It is thus possible to achieve an unequal distribution of torque between the two side gears. In a second embodiment, the desired ratios of the numbers of teeth are achieved by having both side gears provided with end toothings with identical numbers of teeth (z=n), and the differential disc is provided with end toothings with one tooth fewer (z=n−1) on one side and one tooth more (z=n+1) on the other side. By using side gears provided with end toothings with identical numbers of teeth, the number of different parts required for the locking differential is reduced.

I claim:  
     
         1 . A locking differential having a rotatable differential carrier rotatable around an axis, with a pair of spaced-apart side gears contained within the differential carrier and rotatable relative to one another, and having a differential component which co-operates with the side gears by means of alternately-engaging toothings and which is non-rotatably coupled to the differential carrier so as to rotate therewith, wherein: 
 (1) said spaced-apart side gears each comprise end toothings which face one another; and    (2) said differential component comprises a differential disc with two faces, each face comprising end toothings, the end toothings on one of said faces cooperating with the end toothings on one of said side gears, and the end toothings on the other of said faces cooperating with the end toothings on the other of said side gears, with the number of teeth of each pair of inter-engaging end toothings differing by one tooth and with the ratio of the number of teeth of both pairs of inter-engaging end toothings being unequal; and    (3) said differential disc is moveable in a wobbly manner between said side gears so that, by means of diametrically-opposed portions of its two pairs of inter-engaging end toothings, said differential disc engages said end toothings of both of said side gears.    
     
     
         2 . A locking differential according to    claim 1   , wherein said differential disc comprises at least one peripherally-disposed driving element, and said differential carrier comprises off-center longitudinal guiding means, said driving element and said longitudinal guiding means engaging one another so as to non-rotatably couple each to the other.  
     
     
         3 . A locking differential according to either of claims  1  or  2 , wherein said differential carrier comprises a flange and rotatable driving means secured to said differential carrier by said flange, and output shafts are connected to said side gears, said output shafts being rotatably inserted into said differential carrier.  
     
     
         4 . A locking differential according to    claim 2   , wherein three circumferentially-distributed, radially-extending journals are secured to said differential disc and engage three corresponding circumferentially-distributed longitudinal guiding means in said differential carrier.  
     
     
         5 . A locking differential according to    claim 4   , wherein said circumferentially-distributed longitudinal guiding means in said differential carrier comprises rolling members disposed on said journals.  
     
     
         6 . A locking differential according to    claim 4   , wherein said circumferentially-distributed longitudinal guiding means in said differential carrier comprises sliding blocks disposed on said journals.  
     
     
         7 . A locking differential having a rotatable differential carrier rotatable around an axis, with a pair of spaced-apart side gears contained within the differential carrier and rotatable relative to one another, and having a differential component which cooperates with said side gears by means of alternately-engaging toothings and which is non-rotatably coupled to a driveshaft so as to rotate therewith, said driveshaft extending into the differential carrier, wherein: 
 (1) said spaced-apart side gears each comprise end toothings which face one another; and    (2) said differential component comprises a differential disc with two faces, each face comprising end toothings, the end toothings on one of said faces cooperating with the end toothings on one of said side gears, and the end toothings on the other of said faces cooperating with the end toothings on the other of said side gears, with the number of teeth of each pair of inter-engaging end toothings differing by one tooth and with the ratio of the number of teeth of both pairs of inter-engaging end toothings being unequal; and    (3) said differential disc is moveable in a wobbly manner between said side gears so that, by means of diametrically-opposed portions of its two pairs of inter-engaging end toothings, said differential disc engages said end toothings of both of said side gears.    
     
     
         8 . A locking differential according to    claim 7   , wherein said differential disc comprises at least one inner longitudinal guiding means disposed off-center with respect to said differential disc, and at least one driving element is peripherally disposed on said driveshaft, said driving element and said at least one inner longitudinal guiding means engaging one another to non-rotatably couple said differential disc and said driveshaft.  
     
     
         9 . A locking differential according to either of claims  7  or  8 , wherein said differential carrier is freely rotatable with respect to said side gears.  
     
     
         10 . A locking differential according to any one of    claims 7    to    9   , wherein said side gears are rotatably supported in said differential carrier and are each connectable to sideshafts, one of which comprises a hollow shaft extending co-axially with respect to said driveshaft.  
     
     
         11 . A locking differential according to any one of    claims 7    to    10   , wherein said differential disc comprises a plurality of inner grooves and a hub member is disposed on said driveshaft, said hub member comprising a plurality of circumferentially-disposed radial journals which engage said a plurality of inner grooves in said differential disc.  
     
     
         12 . A locking differential according to any one of    claims 7    to    10   , wherein: 
 (1) said differential disc comprises a plurality of inner ball grooves and a hub member is disposed on said driveshaft;  
 (2) a hub member is disposed on said driveshaft, said hub member comprising a plurality of outer ball grooves;  
 (3) a plurality of balls and a ball cage cooperate with said differential disc and said hub member to form a constant-velocity universal joint.  
 
     
     
         13 . A locking differential according to either of claims  1  or  7 , wherein said differential disc comprises two sets of end toothings, each set having the same number of teeth, and one of said side gears comprises a set of end toothings having one tooth less than either of said two sets of end toothings of said differential disc, and the other of said side gears comprises a set of end toothings having one tooth more than either of said two sets of end toothings of said differential disc.  
     
     
         14 . A locking differential according to either of claims  1  or  7 , wherein said each of said side gears comprises a set of end toothings with identical numbers of teeth, and said differential disc comprises two sets of end toothings, one set comprising a set of end toothings having one tooth less than either of said sets of end toothings of said side gears, and the other set comprising a set of end toothings having one tooth more than either of said sets of end toothings of said side gears.  
     
     
         15 . A locking differential according to either of claims  1  or  7 , wherein at least one of said side gears is rotatable relative to said differential carrier and is axially supported in said differential carrier by axial bearing means.  
     
     
         16 . A locking differential according to either of claims  1  or  7 , wherein at least one of said side gears is rotatable relative to said differential carrier and is axially supported in said differential carrier by sliding disc means.  
     
     
         17 . A locking differential according to any either of claims  1  or  7 , wherein at least one of said side gears is rotatable relative to said differential carrier and is axially supported in said differential carrier by friction disc means.  
     
     
         18 . A locking differential according to either of claims  1  or  7 , wherein sealing means are disposed between said differential carrier and all components rotatable with respect to said differential carrier, and viscous fluid at least partially fills the interior of said differential carrier.