Abstract:
A traction drive apparatus is provided for transferring torque from an input rotating shaft to an in-line, or co-axial, output rotating shaft. More specifically, the invention is a gearless, friction drive, in-line, rotating speed reducer or speed increaser for use in a wide variety of rotating equipment applications. The apparatus of the instant invention employs a retainer of a plurality of bearing means to transfer torque from an input shaft to an output shaft, wherein the retainer is either non-rotating or rotating.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention concerns generally with an apparatus and a method for transferring torque from an input rotating shaft to an output rotating shaft. More specifically, the invention is a friction drive rotating speed reducer or speed increaser for use in a wide variety of rotating equipment. 
       BACKGROUND 
       [0002]    Planetary gear systems have found significant use in many applications including automatic car transmissions and industrial equipment, as well as many others. Planetary gear systems are made of a central sun gear that rotates about a longitudinal axis and that is surrounded by one or more sets of planet gears. The planet gears in a plane surround the sun gear with each of their respective peripheral edges engaging the sun gear at its outer surface. A ring gear surrounds the planet gears and engages the peripheral edge of each of the planet gears at their radially outermost point from the longitudinal axis. Each of the planet gears rotates about a planet shaft that forms its own axis. A planet carrier holds all of the planet shafts in their alignment and spatial distribution about the sun gear. The planet carrier is typically a disc or some other structure that is mounted coaxially about the longitudinal axis and can be capable of rotating about the longitudinal axis. 
         [0003]    However, the meshing of gear teeth in many existing planetary gear sets requires overcoming sliding friction that occurs as each gear tooth of one gear meshes with a corresponding tooth on another gear. The friction of this meshing is converted to heat, noise and deformation of the gears, and is therefore not transferred out of the gear set, resulting in a reduced efficiency of the gear set. This reduced efficiency is not satisfactory for many applications and an alternative type of reduction or step-up drive would be beneficial. While design alternatives to standard gear teeth exist that greatly improve the efficiency of such gear designs, such designs still do not provide a high efficiency at a low cost. Furthermore, it would be beneficial for a planetary gear set to achieve any or all of the following as well; a large speed change, the ability to produce any speed change ratio, the capacity for a very high rotational speed, a low manufacturing cost, long component life, very low or essentially no backlash, or any combination of these. These and other advantages are achieved by some or all of the embodiments described herein. 
       SUMMARY OF THE INVENTION 
       [0004]    The systems and methods described herein have several features, no single one of which is solely responsible for the overall desirable attributes. Without limiting the scope as expressed by the claims that follow, the more prominent features of certain embodiments of the invention will now be discussed briefly. 
         [0005]    In one embodiment, the present invention is a speed reducer/increaser organized about a center axis. The speed reducer/increaser comprises a plurality of bearing means; a first shaft member, a second shaft module, a retainer member, a housing, and a positioning means for positioning the second shaft module within the housing. The first shaft member module comprises a first shaft member that has a first shaft proximal end and a first shaft distal end. A first shaft bearing means is disposed on the first shaft member coaxially. The second shaft module comprises a second shaft member having a second proximal end and a second distal end. A second shaft bearing means disposed on the second shaft member coaxially. The second proximal end of the second shaft module is adapted to contact each of the plurality of bearing means. The retainer member is adapted to retain and permit the rotation of each of the plurality of bearing means in a plane that is orthogonal to and positioned coaxially about the center axis. The retainer member has a contoured external surface and a hollow contoured internal surface inclosing an internal space. Each of the plurality of bearing means at least partially extends above the contoured external surface and at least partially extends through the hollow contoured internal surface into the internal space. The housing has an annular space adapted for coaxially enclosing the first shaft module, the retainer member, and the second shaft module. The housing is adapted to permit the first proximal end of the first shaft member and the second distal end of the second shaft member to extend outwardly along the center axis from the housing to permit the rotation of the first shaft member and the second shaft member. The positioning means for positioning the second shaft module within the housing is adapted to permit the proximal end of the second shaft member to contact each of the plurality of bearing means in the internal space of the retainer member with sufficient pressure to transfer torque from the second shaft member to the first shaft member. Either the retainer member is maintained in a non-rotating position within the housing, or the retainer member is disposed on the distal end of the first shaft member and the housing is adapted to permit the rotation of the retainer member while maintaining the alignment of the first shaft member and the second shaft member on the center axis. 
         [0006]    In a further embodiment, the present invention is speed reducer/increaser organized about a center axis. The speed reducer/increaser comprises a first shaft member, a plurality of bearing means, a retainer member, a second shaft member, a cylindrical adaptor, and a housing. The first shaft member has a proximal end and a distal end. The distal end of the first shaft member terminates in a cylindrical rotational housing about the center axis. The cylindrical rotational housing encloses a generally contoured internal bearing surface which broadens toward the distal end. The retainer member has an outer surface, an upper surface, a generally contoured center section, and a flange. The center section has an external contoured surface and a hollow internal contoured zone and is adapted to retain each of the plurality of bearing means in a plane that is orthogonal to and positioned coaxially about the center axis. Each of the plurality of bearing means extends through the contoured external surface and into the hollow internal contoured zone. The retainer member adapted to be at least partially enclosed by said cylindrical rotational housing permitting each of the plurality of bearing means to be in contact said generally contoured internal bearing surface of the cylindrical rotational housing about the center axis at a first contact surface of each bearing means. The flange extends outwardly about the center axis orthogonally beyond the cylindrical rotational housing. The second shaft member is positioned coaxially with the first shaft member. The second shaft member has a second proximal end and a second distal end. The second proximal end is adapted to contact each of the plurality of bearing means extending into the hollow internal contoured zone of the retainer member at a second contact surface of each bearing means. The cylindrical adaptor has a bore. The bore is coaxial with the center axis and has a proximal bearing recess and a distal bearing recess, wherein each bearing recess is adapted to accommodate a bearing. A center wall separates the proximal bearing recess and the distal recess. The center wall has a hole adapted to accommodate the rotation of the second shaft member. The cylindrical adaptor is disposed on the second shaft member. The housing is positioned about the center axis. The housing has an upper housing section and a lower housing section that at least partially encloses and surrounds the cylindrical rotational housing, the plurality of bearing means, the retainer member, and the cylindrical adaptor. The flange of the retainer member is rigidly positioned between the upper housing section and the lower housing section. The upper housing section has a housing bore which is coaxial with the center axis. The housing bore has a proximal zone and a distal zone. The proximal zone has a first bearing recess and a second bearing recess which are separated by a proximal zone wall. The proximal zone wall has a proximal bore which is adapted to accommodate the rotation of the first shaft member. The distal zone is adapted to accommodate the rotation of the cylindrical housing. The cylindrical adaptor is adjustably positioned in the lower housing section. The first shaft member is capable of having a rotational speed about the center axis that is different from a rotational speed of the second shaft member. 
         [0007]    In a still further embodiment, the invention is a speed reducer/increaser organized about a center axis comprising a plurality of bearing means, a first shaft member, a second shaft member, and a housing. The first shaft member has a proximal end and a distal end. The distal end terminates in a generally contoured retainer member about the center axis. The retainer member has an external contoured surface and a hollow internal contoured zone, and is adapted to retain each of the plurality of bearing means in a plane that is orthogonal to and positioned coaxially about the center axis. Each of the bearing means extends above the external contoured surface and below into the hollow internal contoured zone. The second shaft member is positioned coaxially with the first shaft member The second shaft member has a second proximal end and a second distal end. The second proximal end is adapted to contact each of the plurality of bearing means which extend into the hollow internal contoured zone of the retainer member. The housing is positioned about the center axis. The housing comprises an upper housing section and a lower housing section. The upper housing section has a contoured interior zone which has an internal bearing surface that at least partially encloses and surrounds the generally contoured retainer member permitting each of the plurality of bearing means to be in contact the internal bearing surface and is positioned about the center axis. The lower housing section at least partially encloses and surrounds the second shaft member and is rigidly attached to the upper housing section. The first shaft member is capable of having a rotational speed about the center axis that is different from a rotational speed of the second shaft member. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is an exploded view of the second embodiment of the invention with a non-rotating retainer. 
           [0009]      FIG. 2  shows the second embodiment of the invention, wherein (a) is a frontal view and (b) cross-sectional view taken along line  2 A- 2 A in (a). 
           [0010]      FIG. 3  is an exploded view of the first embodiment of the invention with a rotating retainer. 
           [0011]      FIG. 4  shows the first embodiment of the invention, wherein (a) is a frontal view and (b) cross-sectional view taken along line  4 B- 4 B in (a). 
           [0012]      FIG. 5  shows a cross-sectional view of an alternative embodiment of a non-rotating adaptor of the instant invention, herein showing a 3-stage adaptor assembly. 
           [0013]      FIG. 6  shows a cross-sectional view of an alternative embodiment of a non-rotating adaptor of the instant invention, herein showing a 2-stage adaptor assembly. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    With reference to  FIG. 1 , an exploded view of a speed reducer/increaser of the present invention having a non-rotating retainer is shown. The invention is a speed reducer/increaser organized about a center axis comprising a first shaft member  14 , a plurality of bearing means  5 , a retainer member  26 , a second shaft member  46 , a cylindrical adaptor  66 , and a housing ( 56  upper housing section,  58  lower housing section). The plurality of bearing means  5  can be a plurality of ball bearings or cylinders or tapered rollers. As used herein, a plurality of bearing means is at least two such bearing means. The first shaft member  14  has a proximal end  13  and a distal end  22 , and the distal end  22  terminates in a cylindrical rotational housing  20  about the center axis  2 . The cylindrical rotational housing  20  encloses a generally contoured internal bearing surface  19  and broadens toward the distal end  22 . The retainer member  26  has an external contoured surface  32 , generally contoured center section  29 , and a flange  34 . The generally contoured center section  29  has a hollow internal contoured zone  27  and is adapted to retain each of the plurality of bearing means  5  in a plane that is orthogonal to and positioned coaxially about the center axis. Each of the bearing means  5  extends at least partially through the external contoured surface  32  and at least partially into the hollow internal contoured zone  27 . The retainer member  26  is adapted to be at least partially enclosed by the cylindrical rotational housing  20  permitting each of the plurality of bearing means  5  to be in contact with the generally contoured internal bearing surface  19  of the cylindrical rotational housing  20  about the center axis  2  at a first contact surface of each bearing means. The flange  34  extends radially outward from the cylindrical rotational housing  20  and is rigidly fixed between the upper housing section  56  and the lower housing section  58 . The retainer member  26  is rigidly fixed in place between the upper housing and lower housing sections  56  and  58 , respectively, and not permitted to rotate. In one embodiment, flange  34  is notched (see notch  64 ′) to engage with the plurality of fasteners  64  to prevent the rotation of the retainer member  26  relative to the upper and lower housing sections  56  and  58 . Alternatively, the retainer member  26  can be notched to engage either the upper or the lower housing sections  56  and  58 , and the upper and lower housing sections  56  and  58  are rigidly fixed to prevent rotation of the retainer member  26  by means of a clamp (not shown). The second shaft member  46 , or input shaft, is positioned coaxially with the first shaft member  14 . The second shaft member  46  has a second proximal end  48  and a second distal end  50 . The second proximal end  48  is adapted to an outside contour of the bearing means  5  and contacts each of the plurality of bearing means  5  in the hollow internal contoured zone  27  of the retainer member  26  at a second contact surface of each bearing means  5 . The cylindrical adaptor  66  has a bore, and the bore is coaxially aligned with the center axis  2  and has a proximal bearing recess  68  and an optional distal bearing recess  69 . Each bearing recess ( 68 , and the optional bearing recess  69 ) is adapted to accommodate a shaft bearing  60 , and a center wall  67  separates the proximal bearing recess  68  and the optional distal bearing recess  69 . When only a single bearing  60  is used, only a single bearing recess  68  is provided. The center wall  67  has a hole adapted to accommodate the rotation of the second shaft member  46 . The second shaft member  46  is positioned and aligned within the hole in the center wall  67  by the shaft bearings  60  disposed in the proximal bearing recess  68  and the distal bearing recess  69 . Each of the shaft bearings  60  are secured by a retainer ring  62  disposed on the second shaft member in a recess  70  to laterally position the second shaft member  46  within the cylindrical adaptor  66 . The cylindrical adaptor  66  is disposed on the second shaft member  46 . The housing ( 56 ,  58 ) is positioned about the center axis. The housing may be tubular, cylindrical, open cage, or any other shape. The housing (upper housing section  56 , lower housing section  58 ) has an upper housing section  56  and a lower housing section  58 . The upper housing section  56  at least partially encloses and surrounds the cylindrical rotational housing  20 , the plurality of bearing means  5 , the retainer member  26 , and the cylindrical adaptor  66 . The flange  32  of the retainer member  26  is rigidly positioned between the upper housing section  56  and the lower housing section  58 , thereby preventing the rotation of the retainer member  26 . A plurality of fasteners  64  which are equidistantly disposed about the center axis extending through the lower housing section  58  and are secured to the lower housing section  58 . 
         [0015]    In a simplified variation of the instant invention, referring to  FIG. 1 , the features of the cylindrical adaptor  66  are incorporated into the lower housing section  58  as a single rigid body lower housing having at least one bearing recess (i.e., proximal bearing recess  68  and/or distal bearing recess  69 ), wherein the bearing recess is adapted to accommodate a shaft bearing  60 . In this embodiment, a positioning means (not shown) is used for positioning the second shaft member  46  within the single rigid body lower housing to restrict lateral movement of the second shaft member along the center axis. The positioning means can be any means for adjustably positioning the second shaft member  46 , including a manual adjustment to compensate for wear, or a pressure device like compression springs or a contoured spring washer to keep the bearing means  5  in the retainer member  26  and second shaft member  46  in constant pressure. 
         [0016]      FIG. 2(   a ) shows the front view of the speed reducer/increaser of the present invention having a non-rotating retainer. In  FIG. 2(   b ), the cross-sectional view taken along line  2 A- 2 A in  2 ( a ), the upper housing section  56  has a housing bore which is coaxial with the center axis, and has an upper housing proximal zone and an upper housing distal zone. The upper housing proximal zone has a first bearing recess  52  and a second bearing recess  54  separated by an upper housing proximal zone wall  53 . The proximal zone wall  53  has a proximal bore adapted to accommodate the rotation of the first shaft member  14 . The first shaft member shaft  14  is laterally positioned and aligned within the proximal bore in the proximal zone wall  53  by the shaft bearings  60  disposed in the upper housing proximal bearing recess  52  and the upper housing distal bearing recess  53 . The shaft bearings  60  are secured by a retainer ring  62  disposed on the first shaft member  14  in a recess  70 , or by a shoulder raised on the first shaft member  14 , or by some other retaining means such as a pin or a key. The upper housing distal zone  21  is adapted to enclose and accommodate the rotation of the cylindrical rotational housing  20 . 
         [0017]    It is important that the cylindrical adaptor  66  be rigidly positioned within the lower housing section  58 , but it also important to adjust the position of the cylindrical adaptor  66  and second shaft member  46  to maintain sufficient pressure and contact with the bearing means. Thus, the cylindrical adaptor  66  is adjustably positioned in the lower housing section  58  by a positioning means to maintain effective contact and effective constant pressure between the proximal end  48  of the second shaft member  46  and the plurality of bearing means  5 . The positioning means can be any means for adjustably positioning the cylindrical adaptor  66  including a manual adjustment to compensate for wear, or a pressure device like compression springs or a contoured spring washer to keep the assembly comprising the cylindrical adaptor  66  and second shaft member  46  in constant pressure. One such positioning means for manual adjustment comprises disposing threads (not shown) on an outer cylindrical surface of the cylindrical adaptor and disposing threads (not shown) on the inner surface of the lower housing section  58  and providing a screwdriver slot or spanner holes on the distal end (not shown) to move the second shaft member, or input shaft, into tighter (or looser) mesh with the bearing means. 
         [0018]    With reference to  FIG. 3 , an exploded view of a speed reducer/increaser of the present invention having a rotating retainer is shown. The invention is a speed reducer/increaser organized about a center axis comprising a plurality of bearing means  105 , a first shaft member  114 , a second shaft member  128 , and a housing (having an upper housing  136  and a lower housing  142 ). The plurality of bearing means  105  can be a plurality of ball bearings or cylinders or tapered rollers. As used herein, a plurality of bearing means  105  is at least two such bearing means. The first shaft member  114 , or output shaft member, has a proximal end  109  and a distal end  111 . The distal end terminates in a generally contoured retainer member  120  about the center axis  112 . The generally contoured retainer member  120  has an external contoured surface  113  and a hollow internal contoured zone  115 . The generally contoured retainer member  120  is adapted to retain each of the plurality of bearing means  105  in a plane that is orthogonal to and positioned coaxially about the center axis  112 . Each of the bearing means  105  at least partially extends above the external contoured surface  113  and each of the bearing means at least partially extends into the hollow internal contoured zone  115 . The second shaft member  128  is positioned coaxially with the first shaft member  114 . The second shaft member  128  has a second proximal end  130  and a second distal end  129 . The second proximal end  130  is tapered toward the second proximal end  130 . The second proximal end  130  is positioned to contact each of the plurality of bearing means  105  and extends into the hollow internal contoured zone  115  of the generally contoured retainer member  120 . The housing (upper housing section  136 , lower housing section  142 ) is positioned coaxially about the center axis and comprises an upper housing section  136  and a lower housing section  142 . The upper housing section  136  has a contoured interior zone  138  which has an internal bearing surface  140  that encloses and surrounds the generally contoured retainer member  120  permitting each of the plurality of bearing means  105  to be in contact the internal bearing surface  140  and positioned about the center axis. The lower housing section  142  at least partially encloses and surrounds the second shaft member  128 . The second shaft member  128  is laterally positioned in the lower housing section  142  to place the proximal end  130  of the second shaft member  128  in contact with the portion of bearing means  105  extending into the hollow internal contoured zone  115  of the generally contoured retainer member  120 . A plurality of fasteners  152  which are equidistantly disposed about the center axis extend through the upper housing section  136  and are secured to the lower housing section  142 . 
         [0019]      FIG. 4  shows the second embodiment of the invention, wherein  4 ( a ) is a frontal view, and  4 ( b ) cross-sectional view taken along line  4 A- 4 A in  4 ( a ). In  FIG. 4(   b ) the upper housing section  136  has a housing bore which is coaxial with the center axis, and has an upper housing proximal zone and an upper housing distal zone. With reference to  FIG. 4(   b ) the upper housing section  136  has a housing bore which is coaxial with the center axis, and has an upper housing proximal zone and an upper housing distal zone. The upper housing proximal zone has a first bearing recess  132  and a second bearing recess  133  separated by an upper housing zone wall  135 . The upper housing zone wall  135  has a shaft bore adapted to accommodate the rotation of the first shaft member  114 . The first shaft member shaft  114  is positioned and aligned within the shaft bore in the upper housing zone wall  135  by the shaft bearings  144  disposed in first bearing recess  132  and a second bearing recess  135 . The shaft bearing  144  is laterally secured by a retainer ring  146  disposed on the first shaft member  114  in a shaft recess  156  (See  FIG. 3) . The upper housing distal zone is adapted to accommodate the rotation of the generally contoured retainer member  120 . The lower housing section  142  has a bore, and the bore is coaxial with the center axis and has a proximal bearing recess  168  and a distal bearing recess  169 . Each bearing recess ( 168 ,  169 ) is adapted to accommodate a shaft bearing  144 , and a center wall  167  separates the proximal bearing recess  168  and the distal bearing recess  169 . The center wall  167  has a hole adapted to accommodate the rotation of the second shaft member  128 . The second shaft member  128  is positioned and aligned within the hole in the center wall  167  by the shaft bearings  144  disposed in the proximal bearing recess  168  and the distal bearing recess  169 . Each of the shaft bearings  144  are secured by a retainer ring  146  disposed on the second shaft member  128  in recesses  156  (See  FIG. 3 ). The second shaft member  128  is longitudinally aligned within the lower housing section  142  by at least 1 spring ring  148  and one or more spring retainer ring  150  in recess  154  to maintain effective contact and pressure on the second proximal end  130  of the second shaft member  128  to apply pressure to the plurality of bearing means  105 . In an alternate embodiment, at least one or more of the at least one spring ring  148  and one or more spring retainer ring  150  is replaced with a positioning means (not shown in  FIG. 3 , but similar to the cylindrical adaptor  66 , shown in  FIG. 1 ) for manual adjustment of the pressure. The positioning means has a cylindrical body having an outer cylindrical surface, an inside end, an outside end, and a shaft bore coaxial with the center axis. The shaft bore is adapted to accommodate the second shaft member  128 , and the positioning means is adapted to be accommodated within recess  154 . Threads disposed on the outer cylindrical surface of the positioning means and threads disposed on the inner surface of the lower housing section  142  are adapted to permit the adjustment of the pressure on the second proximal end  130  of the second shaft member  128  to apply pressure to the plurality of bearing means  105 . A screwdriver slot or spanner holes disposed on the outside end of the positioning means facilitates manual adjustment to move the second shaft member  128  into tighter (or looser) mesh with the bearing means  105 . 
         [0020]    Additionally, the speed reducer/increaser of the present invention in either of the above embodiments wherein the retainer means is permitted to rotate, or wherein the retainer means is non-rotating can be assembled in stages by use of a modular assembly/design method. A “stage” would represent the assembly of one or more bearing means and one or more retainer means that may or may not be permitted to rotate about the centerline. Furthermore, the retainer member may comprise one or more intermediate stage transmission modules. When present, the intermediate stage transmission module is disposed between the retainer member and the proximal end of the second shaft member. Each of the at least one intermediate stage transmission module comprises a plurality of intermediate stage bearing means, an intermediate stage shaft member disposed coaxially with the first shaft member, and an intermediate stage retainer. The intermediate shaft member has an intermediate stage proximal end adapted to contact each of the plurality of bearing means in the retainer member and has an intermediate stage distal end. The intermediate stage retainer member is disposed coaxially with the first shaft member. The intermediate stage retainer member has a generally contoured intermediate external surface and an intermediate hollow internal contoured zone inclosing an intermediate internal space. Each of the plurality of shaft bearing means is retained in the intermediate stage retainer member such that each shaft bearing means at least partially extends above the contoured intermediate external surface and at least partially extends through the intermediate hollow contoured internal surface into the intermediate internal space. Furthermore, the intermediate internal space is adapted to contact a proximal end of an adjacent intermediate stage transmission module or the second proximal end of the second shaft member. The intermediate shaft retainer member will be either a rotating retainer member or a non-rotating member according to whether the initial retainer member is a rotating retainer member or a non-rotating retainer member. The intermediate stage transmission module is non-rotating when the retainer member is non-rotating. The intermediate stage transmission module is rotating when the retainer member is rotating. These alternatives are illustrated in  FIG. 5  and  FIG. 6  and further discussed hereinbelow. 
         [0021]      FIG. 5  represents a cross section of an alternate embodiment of the non-rotating retainer member/second shaft module described in  FIG. 1 , herein shown as a 3-stage assembly using two intermediate stage transmission modules. In the multi-stage arrangement shown, an axial force applied to any shaft member in the 3-stage assembly is transmitted to the adjacent shaft member to transmit torque and/or rotational motion to an adjacent shaft member. In this embodiment, the retainer members are non-rotating. Referring to  FIG. 5 , a first stage comprises a first stage shaft member  200 , a plurality of bearing means  205 , and a first stage retainer member  220  retaining the bearing means  205  coaxially about a centerline  210 . The second stage comprises a second shaft member  230 , a plurality of bearing means  205 , and a second stage retainer member  240  retaining the plurality of bearing means  205  coaxially about the centerline  210 . The third stage comprises a third stage shaft member  250 , a plurality of bearing means  205 , and a third stage retainer member  260  retaining the bearing means  205  coaxially about the centerline  210 . A fourth shaft member  270  is disposed coaxially about the center axis with sufficient pressure along the center axis to contact the plurality of bearing means  205  in the third stage retainer member  260 . All shaft members  200 ,  230 ,  240 , and  270  have the same centerline axis and are coaxial with the retainer members  220 ,  240 , and  260  about centerline  210 . As disclosed hereinabove, the opposing ends of the shaft members  230 ,  240 , and  270  are contoured to provide an effective contact surface with the plurality of bearing means in each stage. It is believed that the contours on either end of any intermediate shaft members, i.e.,  230  and  250 , will act to maintain their radial position concentric with the rest of the assembly. The intermediate shaft members  230  and  250  do not require ball bearings or bushings to maintain their radial position coincident with the centerline of the other shafts; however, such supporting elements may be used. Thus, an axial force applied to the forth shaft member  270  will transmit torque or rotational motion to shaft members  250 ,  230 , and  200 . By varying the effective diameters of the shaft members and the within the 3-stage module, a speed increase or a speed decrease across the 3-stage module between the first stage shaft member  210  and the fourth shaft member  270  can be achieved. 
         [0022]      FIG. 6  represents a cross section of an alternate embodiment of the rotating retainer member/second shaft module in  FIG. 3  shown as a 2-stage assembly one intermediate stage transmission module. In the multi-stage arrangement shown in  FIG. 6 , an axial force applied to any shaft member in the 2-stage assembly is transmitted to the adjacent shaft member to transmit torque and/or rotational motion to an adjacent shaft member and retainer member. Referring to  FIG. 6 , a first stage comprises a first stage shaft member  300  having a first stage shaft proximal end  302  and having an integral first stage retainer member  301 , a plurality of bearing means  305 , wherein the integral first stage retainer member  301  retains the bearing means  305  coaxially in a fixed orbit about a centerline  310 . The first stage shaft member  300  having the integral first stage retainer member  301  is disposed within a first upper housing section  320  having a contoured bearing surface  321  adapted to contact the bearing means  305  and permit the rotation of the first shaft member  300 . The second stage comprises a second stage shaft member  330  having a second stage proximal end  332 , and, at a second stage distal end, an integral second stage retainer member  331 , a plurality of bearing means  305 . The second stage shaft member  330  having the integral second stage retainer member  331  is disposed within a second upper housing section  340  having a contoured bearing surface  341  adapted to contact the bearing means  305  and permit the rotation of the second shaft member  340 . The second shaft member  340  retaining the plurality of bearing means  305  coaxially in a fixed orbit about a centerline  310 . A third stage shaft member  350  having a third stage shaft proximal end  352  and a third stage shaft distal end  351  is disposed coaxially about the center axis with sufficient pressure along the center axis  310  to contact the plurality of bearing means  305  in the second stage retainer member  331 . All staged shaft members:  300 ,  330 , and  350  share, or are disposed on the same centerline and are coaxial with the retainer members  301 , and  331  about centerline  310 . As disclosed hereinabove, proximal ends  332  and  352  of the shaft members  330  and  350 , respectively, are contoured to provide an effective contact surface with the plurality of bearing means  305  in each stage. It is believed that the contours on the second and third shaft members  330  and  350  will act to maintain their radial position concentric with the rest of the assembly. Thus, the intermediate shaft members  330  and  350  do not require ball bearings or bushings to maintain their radial position coincident with the centerline of the other shafts; however, such supporting elements may be used. Thus, an axial force applied to the forth shaft member  350  will transmit torque or rotational motion to shaft members  330  and  300 . By varying the effective diameters of the shaft members and the within the 2-stage module, a speed increase or a speed decrease across the 2-stage module between the first stage shaft member  300  and the third shaft member  350  can be achieved. 
         [0023]    It is important that in each embodiment that there be an effective amount of axial force applied to each multi-stage arrangement or shaft/retainer combination within each stage of the present invention to provide the motion or rotation throughout the staged shaft member/retainer member combination. In this manner the axial force can be transmitted through all stages. Although a single positioning means for a multi-stage arrangement is sufficient, it is preferred that a positioning means for each individual stage be provided to apply an effective amount of axial force in each stage. Furthermore, the positioning means should be adjustable to compensate for wear of the components. Preferably, the positioning means should be individually adjustable across each stage in a multi-stage arrangement. The positioning means for each individual stage may be any means for adjustably positioning the shaft member relative to the retainer member including a manual adjustment to compensate for wear, or a pressure device like compression springs or a contoured spring washer to keep the staged shaft member/retainer member combination in constant pressure. 
         [0024]    The speed reducer/increaser of the present invention can be fastened to other equipment by attaching the housing to the other equipment by a plurality of conventional fasteners at points positioned radially and evenly distributed about the upper housing zone or the lower housing zone on the outside ends of the housing.