Patent Publication Number: US-2023151876-A1

Title: Continuously variable transmission with radial drive

Description:
FIELD OF THE INVENTION 
     This invention relates to a continuously variable transmission system using variable disk friction drive and a three-mode synchronous system suitable for use in automotive transmission and in other applications requiring a variable mechanical drive. 
     BACKGROUND TO THE INVENTION 
     The current invention relates to improvements over PCT patent application number WO2017143363. The improvements are related to a ratio changing mechanism, as well as extension of ratio range in a three-mode synchronous manner. The improvements are further related to simplify the design to facilitate commercial development and increase mechanical efficiency. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An embodiment of the invention is now described by way of example only and with reference to the accompanying drawings in which: 
         FIG.  1 A  is a rear elevation of a transmission system according to the invention; 
         FIG.  1 B  is a sectional view of a transmission system according to the invention, through section A-A as presented in  FIG.  3 A ; 
         FIGS.  2 A and  2 B  illustrate front and rear elevations of a variator system according to the invention; 
         FIGS.  3 A and  3 B  illustrate front and rear elevations of a variator used in the variator system of  FIGS.  2 A and  2 B ; 
         FIG.  4 A  is a front elevation of a structure unit used in the variator of  FIGS.  3 A and  3 B ; 
         FIG.  4 B  illustrates a front and rear elevation of a bevel unit used in the structure unit of  FIG.  4 A ; 
         FIG.  4 C  is a front elevation of a ratio drive used in the structure unit of  FIG.  4 A ; 
         FIGS.  5 A to  5 C  illustrate front and rear elevations, as well as a sectional view of a structure body used in the structure unit of  FIG.  4 A ; 
         FIGS.  6 A to  6 C  illustrate a front elevation, front view and sectional view of a center unit used in the structure unit of  FIG.  4 A ; 
         FIGS.  6 D and  6 E  illustrate a front and rear elevation of a radial shaft used in the variator of  FIGS.  3 A and  3 B ; 
         FIGS.  7 A to  7 D  illustrate a top and bottom elevation, a rear view and a sectional view of a follower unit used in the variator of  FIGS.  3 A and  3 B ; 
         FIG.  8 A  is a front elevation of a spiral cam used in the variator of  FIGS.  3 A and  3 B ; 
         FIGS.  8 B and  8 C  illustrate a rear elevation and sectional view of a variator input shaft used in the variator of  FIGS.  3 A and  3 B ; 
         FIGS.  9 A and  9 B  illustrate a front elevation and sectional view of a front disk unit of the transmission system of  FIG.  1 B ; 
         FIGS.  10 A and  10 B  illustrate a front elevation and sectional view of a rear disk unit of the transmission system of  FIG.  1 B ; 
         FIGS.  11 A and  11 B  are front and rear elevations of a spring unit of the transmission system of  FIG.  1 B ; 
         FIGS.  13 A and  13 B  illustrate a front and rear elevation of a front casing of the transmission system of  FIG.  1 A ; 
         FIGS.  14 A and  14 B  illustrate a front and rear elevation of a rear casing of the transmission system of  FIG.  1 A ; 
         FIGS.  15 A to  15 D  illustrate a front elevation and sectional view of a three-mode system in accordance with the invention, with front elevations of various system components of the three-mode system; 
         FIGS.  16 A and  16 B  illustrates a front and rear elevation of a mode casing; 
         FIG.  17 A is a sectional view of the transmission system of the invention, through section G-G as presented in  FIG.  16 B ; and 
         FIGS.  17 B to  17 E  are sectional detailed views of a selector unit in neutral and mode 1 to 3 positions. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Transmission System  1  of the Invention 
       FIG.  1 A  presents the transmission system  1  of the invention. The transmission system  1  includes a variator system  3  and a three-mode system  5 . The transmission system of the invention  1  is contained in a front casing  7 , a rear casing  9  and mode casing  11 . 
     Variator System  3   
     The variator system  3 , as can most clearly be seen in  FIG.  2   , includes a spring unit  13 , a front disk unit  15 , a variator  17  and a rear disk unit  19 . 
     Variator  17   
     The variator  17 , as can most clearly be seen in  FIG.  3   , includes a structure unit  19 , three radial shafts  21 , three follower units  23 , two spiral cams  181 , and a variator input shaft  411 . 
     Structure Unit  19   
     Structure unit  19 , as can most clearly be seen in  FIG.  4 A , includes a structure body  25 , a bevel unit  29 , two spiral guides  27 , a ratio drive  31  and a center unit  33 . 
     Structure Body  25   
     The structure body  25 , as can most clearly be seen in  FIG.  5   , includes a circular-like body  35  including three identical cut-out formations  37 , radially spaced evenly at 120 degrees apart. Each cut-out formation  37  terminates at a rim of the body  35  in a bearing pocket  39  with c-clip groove  41  and support rim  43 . Each cut-out formation  37  is bordered at either side thereof by two parallel rib formations  36  extending partially inwardly from the rim of the body  35  towards input shaft  411  axis. Neighbouring rib formations  36  between neighbouring cut-out formations  37  are angularly disposed relative to each other so that such neighbouring rib formations  36  join each other to form a substantially triangular configuration  38  with the rim of the body  35 . 
     At an apex of the substantially triangular configuration  38  is a rounded slot  45  which terminates in a slot bottom  47  including a threaded support hole  49  adjacent the slot  45 , and an enlarged blind hole  48  which is arranged concentric with support hole  49 , and on one side extending into slot  45 . One rib formation  36  bordering each cut-out formation  37  also includes a guide face  53 , extending the length of the rib formation  36 , and two guide steps  51  extending parallel to the guide face  53  on either side thereof and along one side of the cut-out formation  37 . 
     The structure body  25  includes a bevel cut-out  55  configured within one of the substantially triangular configurations  38  between two adjoining rib formations  36  and the rim of the body  35 . The bevel cut-out  55  has a top face  61  and bottom face  63  and includes a blind radial pin hole  57 , narrowing down to a blind oil hole  59  extending radially inwardly from the bevel cut-out  55  and terminating into slot  45 . 
     The body  35  includes two rim faces  67 ,  71  arranged at opposite sides of the rim of the body  35 . Each face  67 ,  71  comprises three raised outer faces  71  which interruptedly extends about the circumference of the rim, and three recessed stepped faces  67  extending between neighbouring outer faces. At one substantially triangular configuration  38 , the rim of the body  35  includes a radial slot  77  extending through the rim parallel to the rim faces  67 ,  71  so as to define two parallel rim flanges  40 . Each rim flange  40  includes a bearing pocket  65  and a concentric, smaller diameter hole  69  extending through the rim flange  40 . The holes  69  protruding through the two rim flanges  40  are aligned. The holes  69  protrude through the recessed step faces  67  of the rim. Each rim flange  40  also includes a bearing pocket  73  and a concentric, smaller diameter hole  75  extending through the rim flange  40  and arranged parallel to and adjacent holes  69 . The holes  75  protruding through the two rim flanges  40  are aligned. The holes  75  protrude through the raised outer faces  71  of the rim. 
     On its outer face  71 , the body  35  includes 3 evenly spaced sets of two large holes  79  and two threaded small holes  81  arranged adjacent the large holes  79 , the sets of holes  79 ,  81  being symmetrical with the axis of the respective bearing pockets  39 . Holes  79  and  81  protrude through the outer face  71  on one side of the rim of the body  35  through to the outer face  71  on the other side of body  35 . 
     On either side of the body  35 , faces  71  include a radially inwardly facing, circular cut-out step  83 , configured concentric with body  35 , creating spiral face  85 . 
     The remainder of features in the body  35  are for weight reduction and clearance purposes with other parts and are not further elaborated on. 
     Bevel Unit  29   
     Bevel unit  29 , as can most clearly be seen in  FIG.  4 B , includes a bevel gear  101  with bearing pockets for locating ball bearings  103  and  105  on either side of the bevel gear  101 . A locating centre pin  107  extends through the ball bearings  103 ,  105  and bevel gear  101  such that the bevel gear  101  is rotatable about the locating centre pin  107 . Center pin  107  includes a center oil hole  109  including a radial hole (not shown) in between bearings  103  and  105  to feed oil to the bearings. On one end, hole  109  is plugged with a grub screw  111 . In the assembled structure unit  19  ( FIG.  4 A ), bevel unit  29  is located within bevel cut-out  55  ( FIG.  5   ) with pin  107  mating with radial pin hole  57 , while the two opposite faces of bearings  103  and  105  are located against faces  61  and  63  respectively. 
     Spiral Guide  27   
     The spiral guide  27  ( FIG.  4 A ) includes a circular ring plate body  87  with an inner face  89  facing the structure body  25  and outer face  91  facing away from the structure body  25 . The spiral guide  27  includes semi-circle holes  93 , which are arranged concentric with holes  79  in the structure body  25 , and countersunk holes (not shown) which are arranged concentric with holes  81  in the structure body  25 . Outer face  91  includes a cut-out  99  within an outer periphery of the spiral guide  27  to allow for clearance of bevel gear  101 . In the assembled structure unit  19 , a spiral guide  27  is bolted to both sides of the rim of body  35  via countersunk bolts  97  in holes  81 . 
     Ratio Drive  31   
     The ratio drive  31 , as can most clearly be seen in  FIG.  4 C , includes a ratio input  113  and spiral drive  115 . The ratio input  113  includes a spur gear  117  with a stepped shaft  119  extending from each side of the spur gear  117 , terminating at one end of the shaft  119  in a square drive  121  and at an opposite end of the shaft  119  in an input extension shaft  127  such that the square drive  121  engages the input extension shaft  127 . A ball bearing  123  is arranged on either side of the spur gear  117 . The ball bearings  123  are maintained in position with the aid of c-clips  125 . The input extension shaft  127  includes a female square drive  129  on one end to engage and drive the male square drive  121  so as to enable ratio input  113 . 
     The spiral drive  115  includes an axially displaceable spur gear  137 , which is mounted to a six-sided shaft  131  via a suitable six-sided center hole  143 , the arrangement being such that the six-sided shaft  131  extends from opposite sides of the spur gear  137 . The six-sided shaft  131  is stepped down at both ends to a smooth shaft (not shown), which is further stepped down to a six-sided shaft  135 . At opposite ends thereof, each shaft  135  terminates in and drives a spur gear  138  via a mating six-sided center hole  139 . Locating ball bearings  133  are arranged intermediate the six-sided shaft  131  and the spur gears  138 . 
     In the assembled structure unit  19  ( FIG.  4 A ), spur gear  117  drives spur gear  137  while being positioned in slot  77  ( FIG.  5 B ), while bearings  133  and  123  are located in bearing pockets  65  and  73  respectively, and spur gears  138  are located between the two spiral guides  27 . 
     Center Unit  33   
     Center unit  33 , as can most clearly be seen in  FIGS.  6 A -  6 C , includes a center body  141 , with three evenly spaced radial studs  143  extending outwardly from the centre body  141  and each carrying bearing inner ring  145 , located via a snap ring  147  in a suitable groove on the stud  143  end. Each radial stud  143  includes a center hole  149  extending into a central bore  151  within center body  141 , with a grub screw  153  with central hole  155  located in the end of each stud  143  to act as an oil nozzle. The area around the base of studs  143  are suitably shaped to provide clearance for bevel gear  191  ( FIG.  6 D ). 
     The center body  141  further includes three equally spaced radial extensions  157  extending from the centre body  141  and arranged between the radial studs  143 . Each extension  157  terminates in a rounded rectangular end  159 , creating front face  175  and rear face  177 . One of the extensions  157  includes a hole  161  extending through the rounded end  159  into central bore  151 , with a cut-out  163  to one side. On the front end, center body  141  includes a boss  165  with a bearing pocket  167  which is configured concentric with and adjacent bore  151 . A needle bearing  169  is located within bearing pocket  167 . Boss  165  includes a step on its front end for locating bearing inner ring  171  and on its front face locates thrust bearing  173  and four oil holes  152  extending into bearing pocket  167 . 
     In the assembled structure unit  19  ( FIG.  4 A ), center unit  33  is located within structure body  25  such that its rounded rectangular ends  159  mate with complimentary slots  45  ( FIG.  5 A ), while front faces  175  are located against slot bottoms  47 . Center unit  33  is orientated in such a way that cut-out  163  is positioned alongside oil hole  59  ( FIG.  5 C ) to make oil flow from the center bore  151  to oil hole  109  possible. Center unit  33  is secured with 3 bolts  179  (see  FIG.  3   ) in support hole  49 , with the bolt heads inside blind hole  48 , while the bolt rim locates against face  177 . 
     Radial Shafts  21   
     The radial shafts  21  ( FIGS.  3 A and  3 B ), as can most clearly be seen in  FIG.  6 D  en 6E, each includes an elongate shaft  199  with 4 circumferentially equally spaced square grooves  201  extending the length of the shaft  199  and a central bore  209  extending through the shaft  199 . The shaft  199  terminates at one end thereof in a boss  197  of increased diameter and a bevel gear  191 , including a needle bearing  193  in its central bore, secured via snap ring  195  in a suitable groove to the shaft  199 . The shaft  199  terminates at an opposite end thereof in a location bearing  203 , maintained in place with a washer  205  and bolt  207  threaded into the central bore  209 . A c-clip  211  bears against an outer periphery of bearing  203 . 
     In the assembled variator  17  ( FIGS.  3 A and  3 B ), radial shafts  21  are connected to the centre unit  33  such that, at one end of the shaft  21 , needle bearing  193  of shaft  21  rotatably engages bearing inner ring  145  of the centre unit  33 , while at an opposite end of the shaft  21 , locating bearing  203  locates in bearing pocket  39 , radially securing it to support rim  43  via c-clip  211  engaged in c-clip groove  41 . 
     Follower Unit  23   
     The follower units  23 , as can most clearly be seen in  FIG.  7   , are slidingly mounted to radial shafts  21 . Each follower unit  23  includes a traction roller unit  213  and a follower housing unit  215 . 
     The traction roller unit  213  includes a roller  216  including a disk  217  with outer drive rim  219 , a center bore  221  narrowing down to a splined hole  223  including 4 internal square splines  225  inside a bush  227 , including a step  229  and a c-clip groove  231  at the end of the bush  227 . A ball bearing  233  is located about bush  227  between step  229  and a spacer  235  which is located on the other side against c-clip  237  located in c-clip groove  231 . 
     Follower housing unit  215  includes a roller housing  239 , a slider  241 , two top cam followers  243 , two bottom cam followers  247  and a slide plate  245 . The cam followers  243  and  247  are of the rotating type which includes a needle bearing around an integrated center threaded shaft for mounting purposes. A typical standard bearing supplier part number is SKF KRV16 for clarity purposes. 
     The roller housing  239  includes a rectangular body  249  including circular formations  251  on each side, a semi-circular boss  253  on top, a central bore  255  with an internal step  257  at the bottom, and a c-clip groove  259  locating c-clip  260  at the top of the bore  255 . On both the front sides, body  249  includes a circular recess  261  with concentric threaded hole  263 . 
     Slider  241  includes a rectangular body  265  including two raised formations  267  on its rear face  269 , creating inside slide faces  270 , chamfers  271  on bottom corners of the raised formations  267 , and a shallow slot  273  on its front face  275 . Slider  241  further includes two countersunk holes (not shown) on rear face  269  locating two counter sunk bolts  277 , two recesses  279  with threaded concentric holes  281  on either side, a recess  283  locating the complementary shaped slide plate  245 , and a chamfer  285  on the rear face  269  bottom. Front face  275  includes a semi-circle groove  276  to provide clearance for disk  217 . 
     In the assembled follower unit  23 , the traction roller unit  213  is rotatably located inside the housing unit  215  by locating ball bearing  233  in central bore  255  between internal step  257  and c-clip  260 . Slider  241  is attached to follower housing unit  215  by locating the rear of the rectangular body  249  in shallow slot  273  by securing bolts  277  in threaded holes (not shown) in the rear of rectangular body  249 . Cam followers  243  are located in threaded holes  263 , flush with the base of recess  261 , while cam followers  247  are located in threaded holes  281 , flush with the base of recess  279 . 
     In the assembled variator  17  ( FIGS.  3 A and  3 B ), follower units  23  are axially slidably located within the cut outs  37  of structure unit  19  ( FIGS.  5 A to  5 C ). Each follower unit  23  slidably engages a radial shaft  21  such that shaft  199  protrudes through hole  223  of follower unit  23 , while roller  216  is driven rotatably by sliding engagement of its square splines  225  with square grooves  201  of shaft  199 . The follower units  23  are prevented from rotation relative to the structure unit  19 , by the slidable mating of guide steps  51  with slide faces  270  and the mating of guide face  53  with slide plate  245 . 
     Spiral Cams  181   
     The spiral cam  181 , as can most clearly be seen in  FIG.  8 A , includes a disk  287  including an outer rim face  311 , two opposing side faces  313 , and spur gear teeth  289  on a section of its perimeter. The spiral cam  181  further includes three evenly spaced cam cut-outs  301 , each cut-out  301  including a top cam  303  and a bottom cam  305  with the top and bottom cams joined together with shapes which allows for clearance with other moving parts. Disk  287  includes a center hole  307  with chamfers  309  on either side. 
     In the assembled variator  17 , spiral cams  181  are rotatably located in structure unit  19  with its rim face  311  mating with cut-out step  83  ( FIG.  5 B ) and located between spiral face  85  and the inner face  89  of plate body  87 , while its gear teeth  289  meshes and are driven by spur gear  138  of ratio drive  31 . 
       FIG.  1 B  presents the follower units  23  in their maximum radial position. 
     In order to regulate the radial position of follower units  23 , each cam follower  243 , protruding into cut-out  301 , engage and roll on top cam  303 , while cam followers  247 , protruding into cut-out  301 , engage and roll on bottom cam  305 . As spiral cam  181  is rotated in the direction of arrow  307 , top cam  303  in line contact with cam followers  243  is used to position follower units  23  in a radial direction towards the center hole  307  axis. As spiral cam  181  is rotated in the direction of arrow  309 , bottom cam  305  in line contact with cam followers  247 , is used to position follower units  23  in a radial direction away from the center hole  307  axis. 
     The profile of the top cam  303  and bottom cam  305  is such that all the cam followers  243  and  247  remain in line contact with the respective cams in all radial positions of the follower units  23 . The shape of cut-out  301  is of such a nature that it allows for follower  243 , follower  247 , roller  216  and circular formations  251  to freely operate within cut-out  301  in all radial positions of follower unit  23 . 
     In cost effective solutions cam followers  247  and  247  may be fixed cam surfaces in sliding contact with top cam  303  and a bottom cam  305 . 
     Variator Input Shaft  411   
     The variator input shaft  411 , as can most clearly be seen in  FIGS.  8 B and  8 C , includes a bevel gear shaft  413  including a central tube  415  with a central bore  417  and four evenly spaced oil holes  418 . Shaft  413  terminates at one end thereof in a bevel gear  419 , and a bearing pocket  421  adjacent the bevel gear  419  in an enlarged tube section  423  with outer face  424  including four evenly spaced oil holes  426 . At an opposite end thereof, shaft  413  terminates in a c-clip groove  425  and external splines  427  (splines not shown), a connector tube  429 , a c-clip  431 , a front needle bearing  433  and a rear needle bearing  435 . Connector tube  429  includes a tube body  437  including a central bore  439 , rear end  440 , a step  441 , a bearing pocket  443  and internal splines  445  on its end (splines not shown). 
     In the assembled variator input shaft  411 , bevel gear shaft  413  is attached to connector tube  429  via the mating of external splines  427  and internal splines  445  with the front end of connector tube  429  bearing against c-clip  431 , which is located in c-clip groove  425 , while needle bearing  435  is located in bearing pocket  443  between step  441  and the rear end of bevel gear shaft  413 . Needle bearing  433  is located in bearing pocket  421 . 
     In the assembled variator  17 , as can most clearly be seen in  FIG.  1 B , variator input shaft  411  is rotatably located in center unit  33  via the mating of central tube  415  with needle bearing  169  while the c-clip  431  is located against thrust bearing  173 . Variator input shaft  411  drives the three radial shafts  21  via the meshing of bevel gear  419  simultaneously with the three bevel gears  191  of radial shafts  21 . 
     Front Disk Unit  15   
     Front disk unit  15 , as can most clearly be seen in  FIGS.  9 A and  9 B , includes a front disk  311 , a ring bevel gear  313 , a spherical thrust bearing  315 , a needle bearing  317  and a snap ring  319 . 
     Front disk  311  includes a circular body  321  including a front flat face  323 , a rear face  340 , a step on its outer rim  327  creating face  325  with six circumferential countersunk holes  339 , a center bearing pocket  329  with a snap ring groove  331  on one side and a step  333  on the other side, and a rear circular rim extrusion  335  creating a bearing pocket  337 . 
     Ring bevel gear  313  includes a bevel gear  341 , including a center bore  343 , located and mating with outer rim  327 , a step  345  complimentary shaped and mating with face  325  and six threaded circumferential holes  347  in step  345  concentric with holes  339 . 
     In the assembled front disk unit  15 , spherical thrust bearing  315  is located in bearing pocket  337  with its front face against face  340 , needle bearing  317  is located in bearing pocket  329  between step  333  and snap ring  319  located in snap ring groove  331 , while six countersunk bolts  349  secured in holes  339  and  347  secure ring bevel gear  313  onto front disk  311 . For clarity, spherical thrust bearing  315  may be a standard bearing with bearing number SKF 29412 or any other standard thrust bearing like a ball thrust bearing or taper roller bearing. 
     Rear Disk Unit  19   
     Rear disk unit  19 , as can most clearly be seen in  FIGS.  10 A and  10 B , is identical to front disk unit  15  except for the differences presented below. Rear disk unit  19  includes rear disk  351 , which is identical to front disk  311 , except for the following differences. Body  321  includes a center bore hollow shaft extension  353  with center bore  355  and rear face  361 . On front flat face  323 , body  321  includes a needle bearing pocket  357  locating needle bearing  359  concentric with center bore  355 . Located fixed and flush with face  361  on extension  353 , by any drivable suitable means like splines (not shown), is a gear unit  363 . Gear unit  363  includes a helical gear  365  fixed to a dog clutch disk  367  via a tube  369 . Dog clutch disk  367  includes dog clutch teeth  371  similar to the dog clutch teeth found in automotive manual and automated manual transmissions. 
     Spring Unit  13   
     Spring unit  13 , as can most clearly be seen in  FIGS.  11 A and  11 B , includes a spring holder  373  and eight spring packs  375 , each including an inner compression coil spring  377  with front face  381  and rear face (not shown) located against face  383 ; and concentric with spring  377  an outer compression coil spring  379  with front face  385  and rear face (not shown) located against face  383 .  FIG.  11 B  presents the spring unit  13  with two spring packs  375  hidden for clarity. 
     Spring holder  373  includes a circular body  387  including on its front face  389 , eight evenly spaced spring pockets  391  with bottom faces  383  on a stepped face  393  and a central bore  405  including a step  407 . Circular body  387  also includes a rear face  395 , including a multi-stepped formation  397  terminating in bearing pocket  401  with bottom face  403  including a boss  409  around central bore  405 . 
     In the assembled variator system  3 , as can most clearly be seen in  FIG.  1    and  FIG.  17 A , front disk unit  15  is located rotatably and concentric with spring unit  13  via the location of spherical thrust bearing  315  about boss  409  with its rear face against face  403 . Front disk unit  15  is also rotatably located around center unit  33  of variator  17  through mating of needle bearing  317  with inner ring  171 , while the front flat face  323  of front disk unit  15  is in traction drive line contact with the outer drive rim  219  of follower unit  23  of variator  17 . 
     Rear disk unit  19  is rotatably and concentric located around the variator input shaft  411  of variator  17  via the mating of outer face  424  of shaft  411  with needle bearing  359  of rear disk unit  19 , while the front flat face  323  of rear disk unit  19  is in traction drive line contact with the outer drive rim  219  of follower unit  23  of variator  17 . 
     Front Casing  7   
     Front casing  7 , as can most clearly be seen in  FIG.  13   , includes a circular body  449  including a rear face  477 , a rim  451  with and external step  453  on its front end  455 , a bottom face  457  including eight evenly spaced raised ribs  459 , a center raised face  461 , outer raised faces  463  including semi-circular cut-outs  465 , six evenly spaced bosses  467  with center holes  469 . Raised face  461  carries a cylindrical extrusion  471  with center bore  473  while an inner ring  475  is located around extrusion  471 . Each hole  469  locates a bolt  479  with the bolt  479  heads located against face  477 . 
     Rear Casing  9   
     Rear casing  9 , as can most clearly be seen in  FIG.  14   , includes a circular body  481  including a front face  483 , a rim  485  with an internal step  487  on its front end  489 , a bottom face  491  including six evenly spaced rib formations  493  including two tapered ribs  495 , a raised face  497  and a boss  499  with internal threaded hole  501 , a raised face  521  with an oil seal pocket and center hole, locating oil seal  523 , while the rib formations  493  terminate in a center raised face  503 . 
     Raised face  503  includes a center bore  511 , a casing rim  505  extending to face  491  as well as in the opposite direction to terminate in face  506 , a rim bearing pocket  507  with bottom face  509  and a blind hole  619 . Casing rim  505  is suitably shaped and has sections concentric with bearing pocket  507  and center bore  511  to enclose the components of the three-mode system  5 . Front face  483  includes a multi-step formation  513 , terminating in face  515  including a boss  517  with its center bore larger and concentric with bore  511 , and locating needle bearing  519 . 
     In the assembled transmission system of the invention  1 , spring unit  13  is located in front casing  7  with central bore  405  axially slidably located around inner ring  475 , while the front face  381  of inner compression coil spring  377  and the front face  385  of outer compression coil spring  379  bear against bottom face  457  while being concentric with circular cut-outs  465 . Moreover, rear disk unit  19  is rotatably located in rear casing  9  with the spherical thrust bearing  315  of rear disk unit  19  bearing against face  515  of rear casing  9 , while the inner diameter of spherical thrust bearing  315  is located around boss  517  and needle bearing  519  mates rotatably with shaft extension  353 . 
     The front casing  7  and rear casing  9  are clamped together through bolts  479  of the front casing  7  threading into threaded holes  501  of the rear casing  9 , while the two complementary peripheral external step  453  and internal step  487  engage each other. 
     During operation of the transmission system of the invention  1 , under the compressive force of the compression coil spring  377  and  379 , rollers  216  are clamped in line contact traction drive between the front flat faces  323  of front disk unit  15  and rear disk unit  19 . 
     During operation the variator  17  functions as follows: 
     The variator input shaft  411  drives the three radial shafts  21  via bevel gear  419  meshing with the three bevel gears  191 . The three radial shafts  21  each drive a roller  216  which in turn traction drives both the front disk unit  15  and rear disk unit  19 . The rear disk unit  19  serves as an output and the output of the front disk unit  15  is combined with the rear disk unit  19  via bevel unit  29 . 
     The ratio between input shaft  411  and rear disk unit  19  is changed by rotating input extension shaft  127  (via some power source not shown) which rotates the spiral cams  181  via the ratio drive  31 . The rotating spiral cams  181  regulate the radial position of the rollers  216  via the follower units  23 . The radial position of the rollers  216 , and thus its line contact radius on the front disk  311  and rear disk  351  flat front faces  323 , is directly related to the ratio between input shaft  411  and rear disk unit  19 . 
     As roller  216  has a tendency to always move by its own force to a larger radius on the front disk unit  15  and rear disk unit  19  during operation, cam followers  247  and bottom cam  305  may be eliminated to simplify the design. The variator system  3  can be used as a stand-alone mechanical variator in industrial and electric vehicle applications. 
     It is of importance that the traction fluid oil used in the variator system  17  reach all the relevant moving parts, but most importantly ensures an oil film in the line contact traction drive between the roller  216  rim  219  and front disk  15  and rear disk  19  front flat faces  323 . To this end, traction fluid oil may be supplied by an external pump through a hole (not shown) in the rear casing  9  to deliver oil to center oil hole  109  (grub screw  111  is removed), which will deliver oil to central bore  151  and central hole  155 . From central bore  151  oil is also distributed to oil holes  152 , which feeds oil to the base of front disk  15  and to oil holes  426  (via oil holes  418 ), which feeds oil to the base of rear disk  19 . Through the centrifugal force of the rotating front disk  15  and rear disk  19 , the oil is then distributed over the whole faces  323  of the respective disks to provide the required oil film. Note that in all the oil flow passages, channels, holes, clearances and nozzles, appropriate restrictions like oil seals or o-rings or nozzle sizes may be employed to optimize the oil flow rate to deliver the oil requirements to all components. 
     Three-Mode System  5   
     The three-mode system  5 , as can most clearly be seen in  FIGS.  15 A to  15 D , includes a mode shaft unit  527 , a direct input shaft  529 , a transmission out shaft  531 , a reverse idler  533  and a selector unit  547 . 
     Mode Shaft Unit  527   
     Mode shaft unit  527  includes a shaft  535  terminating at one end in helical gear  537 , terminating at an opposite end in helical gear  539 , and including spur gear  541  arranged intermediate helical gear  537  and helical gear  539 . Each shaft end carries a taper roller bearing  543  and  545 . 
     Direct Input Shaft  529   
     Direct input shaft  529  includes a shaft  549 , with rear end  550 , including a disk  551  carrying dog clutch teeth  553  on its outer rim and shaft extension  555  on its front end. 
     Transmission Out Shaft  531   
     Transmission out shaft  531  includes an output shaft  557  and helical idler  573 . Output shaft  557 , which locates taper roller bearings  571  and  572 , includes a stepped shaft  559  with front face  565  including a boss  561  with front face  585  and dog clutch teeth  563  on its outer rim; as well as an internal boss  567  protruding from face  565 , including a bearing pocket locating needle bearing  569 . Taper roller bearing  571  is located on one side of helical idler  573  against stepped shaft  559 . 
     Helical idler  573  includes a helical gear  575  including an internal bore  577  on one side, locating needle bearing  579 , and on the other side a disk  581  including dog clutch teeth  583  on its rim. Helical idler  573  is rotatably located concentric with stepped shaft  559  via the mating of needle bearing  579  with stepped shaft  559 , while being located between taper roller bearing  571  and face  585 . 
     Selector Unit  547   
     Selector unit  547  includes a spur gear  587  extending about its circumference, including a front face  593  and a rear face  595 . A selector groove  589  extends from front face  593  and terminates in front face  597 . A center bore  596  extends through selector unit  547  and includes a first section of internal dog clutch teeth  591  approximate face  597 , and a second section of internal dog clutch teeth  601 , approximate face  595 , identical to and aligned with teeth  591 , with a smooth bore  603  intermediate teeth  591  and  601 , with bore  603  having a diameter that is larger than the outer diameter of internal dog clutch teeth  591 . 
     Reverse Idler  533   
     Reverse idler  533  includes idler shaft  602  including shaft end  607  on one end and shaft end  609  on the opposite end, semi-circular cut-out  605  approximate shaft end  607 , a reverse spur gear  611  mounted on shaft  602  including a selector groove  613 , a center bore  615  locating needle bearing  617 . Reverse spur gear  611  is rotatably and axially slidably located on shaft  602  via the mating of needle bearing  617  with shaft  602 . 
     The profiles and number of teeth of external dog clutch teeth  583 ,  563 ,  553  and  371  are identical. The profiles and number of teeth of internal dog clutch teeth  591  and  601  are identical and aligned to enable dog clutch teeth  591  and  601  to slide over dog clutch teeth  583 ,  563 ,  553  and  371  and engage them as is common practice in manual and automated manual transmissions. All above dog clutch teeth may include teeth rounding on one or more side to facilitate engagement, which is also common practice in manual and automated manual transmissions. 
     Assembled Three-Mode System  5   
     In the assembled three-mode system  5 , as can most clearly be seen in  FIG.  17 A , direct input shaft  529  is rotatably and concentric located with reference to variator input shaft  411  via the mating of shaft  549  with needle bearings  433  and  435 . Transmission out shaft  531  is rotatably and concentric located with reference to variator input shaft  411  via the mating of needle bearing  569  and shaft extension  555 . Mode shaft unit  527  is rotatably located in a rear casing  9  via taper roller bearing  545  located in bearing pocket  507 , against face  509 , while helical gear  539  meshes with helical gear  575 . Reverse idler  533  is located in rear casing  9  via the location of shaft end  609  in blind hole  619  orientated in such a way that semi-circular cut-out  605  provide clearance for helical gear  539 . 
     Selector unit  547  and reverse spur gear  611  are independently axially positioned via selector forks and their driving means (not shown) engaging their respective selector grooves  589  and  613  respectively as is common practice in manual and automated manual transmissions 
     Mode Casing  11   
     Mode casing  11 , as can most clearly be seen in  FIG.  16   , includes rear face  623  including boss  625 , boss  627 , boss  629  including a center bore  631 , a bearing pocket  633  between the center bore  631  and rear face  635  of boss  629 , a bearing pocket  637  between center bore  631  and inner face  639 , a bearing pocket  641  inside boss  625  on face  639 , a blind hole  643  inside boss  627  on face  639 , a casing rim  645  concentrically shaped around boss  625 , boss  627 , and boss  629  including a lip  647 , around boss  629  on the front face  649  of rim  645 . The lip  647  and rim  645  is of such a shape that face  649  is complimentary shaped and mates and are located against casing rim  505  face  506  of rear casing  9 . 
     In the assembled transmission system of the invention  1 , taper roller bearing  571  of transmission out shaft  531  ( FIG.  15 A ) is located in bearing pocket  637  and taper roller bearing  572  in bearing pocket  633 , taper roller bearing  543  is located in bearing pocket  641 , while shaft end  607  is located in blind hole  643 . 
     Transmission System of the Invention  1  Operation 
     For the explanation below it is assumed that the ratio of the variator  17 , that is the ratio between variator input shaft  411  and dog clutch teeth  371  of rear disk unit  19  can be adjusted from 3:1 to 1:1 by rotation of input extension shaft  127 . It is also assumed that the gear ratio between helical gear  365  and helical idler  573  via mode shaft unit  527  is 1:3. The position of rollers  216  in  FIG.  13    refers to the 1:1 ratio and the position of rollers  216  in  FIG.  17 A  to the 1:3 ratio. However above ratios may be any suitable ratios. 
     Single Clutch Embodiment 
     In this embodiment of the invention  1 , the rear end  550  of direct input shaft  529  and rear end  440  of variator input shaft  411  are coupled/fixed together, as well as coupled to a standard automotive automated single clutch system (not shown) as is commonly found in automated manual automotive transmissions. The single clutch system allows for the selective disengagement or partially or full coupling of rear end  550  to the power source via an integrated wet or dry clutch, usually an internal combustion engine in a typical automotive application. 
     Selector Unit  547  Position: Neutral 
     The neutral position of selector unit  547  is presented in  FIG.  17 B  where only dog clutch teeth  591  is engaged with dog clutch teeth  563  and the transmission out shaft  531  is not coupled to any other components and can freely rotate. In this position dog clutch teeth  553  is positioned between dog clutch teeth  371  of rear disk unit  19  and dog clutch teeth  553  without engaging them while reverse idler  533  is in the position of  FIG.  15 B  with its reverse spur gear  611  not meshing with any other gears. 
     Selector Unit  547  Position: Mode 1 
     This presents the pull away mode with the ratio of the variator  17  at 3:1 and the selector unit  547  in the position of  FIG.  17 C , representing mode 1, where dog clutch teeth  563  and  591  are engaged, as well as dog clutch teeth  601  and  371 , therefore coupling the transmission out shaft  531  to rear disk unit  19 . Via the single clutch system, from a disengaged state, rear end  440  of shaft  411  can now gradually be coupled to the power source, and transmission out shaft  531  will reach a speed of one third of the power source. The ratio of the variator  17  can now gradually be adjusted from the current 3:1 to 1:1 for the transmission out shaft  531  to reach the same speed as the power source. Note that dog clutch teeth  553  will now also rotate at the same speed as the power source due to the fixed coupling between rear end  550  and  440 . 
     Selector Unit  547  Position: Mode 2 
     By momentarily cutting the power source power electronically and disengaging the single clutch system, selector unit  547  can be moved to the position in  FIG.  17 D , representing mode 2, where dog clutch teeth  563  and  591  are engaged, as well as dog clutch teeth  601  and  553 , therefore coupling the transmission output shaft  531  direct to the input shaft  529 , rear end  550  in a 1:1 ratio. After selector unit  547  reaches above position, the single clutch system is re-engaged and power source power is restored. In this position the variator  17  does not transmit any power and is not coupled to transmission out shaft  531 . 
     Selector Unit  547  Position: Mode 3 
     With the selector unit  547  still in mode 2, the variator  17  is now adjusted from its current ratio of 1:1 to a ratio of 3:1. In this ratio the dog clutch teeth  583  of helical idler  573  will rotate at the same speed (1:1 ratio) as the power source since the variator current ratio of 3:1 and the 1:3 gear ratio (between helical gear  365  and helical idler  573  via mode shaft unit  527 ) result in a 1:1 ratio. Note there is ample time for variator  17  to do above ratio adjustment from 1:1 to 3:1 while power from the power source to the transmission out shaft  531  is being transmitted according to mode 2. 
     By momentarily cutting the power source power electronically and disengaging the single clutch system, selector unit  547  can be move to the position in  FIG.  17 E , representing mode 3, where dog clutch teeth  563  and  591  are engaged as well as dog clutch teeth  591  and  583  therefore coupling the transmission out shaft  531  to rear disk unit  19  via mode shaft unit  527 . After selector unit  547  reaches above position, the single clutch system is re-engaged and the power source is restored, creating a 1:1 ratio between the power source and transmission out shaft  531  as explained above. 
     The ratio of the variator  17  can now gradually be adjusted from the current 3:1 to 1:1 for the transmission out shaft  531  to reach three times the speed of the power source (1:1 ratio of variator coupled to 1:3 ratio via mode shaft unit  527  to transmission out shaft  531 ). 
     Reverse 
     With the single clutch system disengaged and the selector unit  547  in the neutral position of  FIG.  17 B  and variator  17  in the 3:1 ratio, reverse spur gear  611  can be moved to the right from its position in  FIG.  15 B  for its teeth to simultaneously engage the teeth of spur gear  541  and spur gear  587 . When the single clutch system is now engaged the power source will drive the transmission out shaft  531  in a -3:1 ratio (opposite direction) via mode shaft unit  527 . Note that the variator  17  can now gradually change its ratio to 1:1 to provide a variable reverse. 
     Ratio Range 
     The complete ratio range of the transmission system of the invention  1  is generated by a low ratio, with selector unit  547  in mode 1 and variator  17  in a 3:1 ratio, resulting in a ratio from power source to transmission out shaft  531  of 3:1; to a high ratio where selector unit  547  is in mode 1 and variator  17  in a 1:1 ratio, resulting in a ratio from power source to transmission out shaft  531  of 1:3 - thus a ratio variation of 1:3 to 3:1 providing a ratio range of 9 which is in line with current high end automotive 9 and 10 speed dual clutch and automatic transmissions. 
     Dual Clutch Embodiment 
     In this embodiment of the invention  1 , the rear end  550  of direct input shaft  529  and rear end  440  of variator input shaft  411  are NOT coupled or fixed together, but coupled to a standard automotive dual clutch system (not shown) as is commonly found in dual clutch automotive transmissions. The dual clutch system allows for the selective disengagement or partially or full coupling of either rear end  550  or rear end  440  or both to the power source via two integrated wet or dry clutches, usually to an internal combustion engine in a typical automotive application. For explanation purposes, the first clutch of the dual clutch system is associated with rear end  440  and the second clutch with rear end  550 . Further, in this embodiment, disk  551  and its dog clutch teeth  553  are eliminated from direct input shaft  529 , while direct input shaft  529  is permanently fixed to output shaft  557  of transmission output shaft  531 . 
     In the sections below only the difference in the operating modes with respect to the single clutch embodiment will be discussed while all other functioning is the same as in the single clutch embodiment. 
     Selector Unit  547  Position: Mode1 (Dual Clutch) 
     With the selector  547  in the position of  FIG.  17 C  and with the second clutch disengaged, via the first clutch engaging, rear end  440  can now gradually be coupled to the power source and transmission output shaft  531  will reach a speed of one third of the power source. The variator  17  can now be adjusted to a 1:1 ratio for the transmission output shaft  531  to reach the same speed as the power source 
     Selector Unit  547  Position: Mode 2 (Dual Clutch) 
     The second clutch engages while simultaneously first clutch disengages to provide uninterrupted power transfer between the power source and the transmission output shaft  531 . This clutch engagement/disengagement overlap is common practice in automotive dual clutch transmissions to provide uninterrupted power and torque transfer. After the above, selector unit  547  is moved to the position in  FIG.  17 D  and thereafter the first clutch is engaged to keep the variator  17  running but not connected to the transmission output shaft  531 . The variator  17  can now be adjusted from its current 1:1 ratio to a 3:1 ratio. 
     Selector Unit  547  Position: Mode 3 (Dual Clutch) 
     After variator  17  reaches its 3:1 ratio, the first clutch is disengaged and right thereafter selector unit  547  is moved to the position in  FIG.  17 E . Thereafter the first clutch engages while simultaneously second clutch disengages to provide uninterrupted power transfer between the power source and the transmission out shaft  531 . 
     In both the single clutch and dual clutch embodiments, the selector unit  547  in its transition between the respective modes are engaging dog clutch teeth, all rotating at the same speed and direction when the respective mode change takes place thus affecting synchronous mode changes. Synchronous mode changes have very significant advantages in automotive transmission implementation facilitating very quick shifting times and eliminating shock loads. In the case of the dual clutch embodiment, uninterrupted power and torque is maintained throughout all mode changes.