Abstract:
A rotary motor shaft extends through a rheological brake unit through which variable braking resistance to rotation of the motor shaft is applied while it undergoes rotation in response to torque mechanically applied thereto in sequence through a peripheral gear by a selected pair of diagonally aligned electro-magnetically energized push-rod actuators adjustably positioned axially along a varying diameter section of the gear under electrical control for stroke change to yield a variable output torque.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application is a continuation-in-part of U.S. Nonprovisional application Ser. No. 10/807,580, filed Mar. 23, 2004 now abandoned, entitled “Direct Drive Hybrid Rotary Motor.” incorporated herein by reference. 

   STATEMENT OF GOVERNMENT INTEREST 
   The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor. 

   The present invention relates generally to an electro-mechanically controlled, electro-magnetic conversion type of rotary motor. 
   BACKGROUND OF THE INVENTION 
   Electromagnetic drive motors with operational phase controls are generally known in the art as disclosed for example in U.S. Pat. No. 5,602,434 to Riedl, involving use of electromagnetic actuator rods engageable with a rotor under phase control to induce rotation thereof. 
   An important object of the present invention is to provide an electrically powered motor having plural components matched to the output torque load being applied in mechanical impedance manner for enhancing electro-motive energy conversion. 
   SUMMARY OF THE INVENTION 
   Pursuant to the present invention, an electric motor has an output shaft connected to a sloped lobe gear having peripheral gear teeth that varies in diameter along an axial end section thereof. Torque is applied to the output shaft by engagement of said variable diameter end section of the gear with push rods projecting from electromagnetic actuators positioned in angular spaced relation to each other about the output shaft on rail supports anchored to a rheological brake unit through which the output shaft extends. Under control applied through magnetic fields to rheological fluid within the brake unit, braking effect is removed from the gear during a free-wheeling operational phase. Electrical energy is also applied to the actuators for mechanically imparting torque to the output shaft through a pair of aligned push-rods engaging the peripheral gear at an axial location along the variable diameter end section selected under stroke control for selectively varied conversion of drive force into the torque applied to the output shaft. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     A more complete appreciation of the invention and many of its attendant advantages will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing wherein: 
       FIG. 1  is a side elevation view of a rotary drive motor constructed in accordance with one embodiment of the present invention; 
       FIG. 2  is a front elevation view of the rotary drive motor illustrated in  FIG. 1 ; 
       FIG. 3  is a partial side section view taken substantially through a plane indicated by section line  3 - 3  in  FIG. 1 ; and 
       FIG. 4  is an operational diagram of a rotary motor drive system corresponding to that associated with the rotary drive motor illustrated in  FIGS. 1 ,  2  and  3 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawing in detail,  FIG. 1  illustrates a rotary drive motor  10  having an axially elongated output rotor shaft  12  with a small diameter end  14  and an opposite larger diameter base end  16 . According to the embodiment shown in  FIG. 1 , a clutch-brake unit  18  is positioned on an end section  20  of the shaft  12  adjacent the base end  16 , in abutment with a thrust bearing component  22 . A torque drive imparting assembly generally referred to by reference numeral  24  is positioned on the shaft  12  between the unit  18  and a small diameter shaft end section  26  at the axial shaft end  14 . 
   As shown in  FIG. 2 , the torque drive imparting assembly  24  includes four actuator units  28  positioned in 90° angular relation to each other about the shaft  12 . Each of such actuator units  28  includes a pair of cylindrical actuator devices  30  held in close parallel spaced relation to each other within a support  32 . Each of the actuator supports  32  as shown in  FIGS. 1 and 2  is adjustably positioned within an elongated rail  34  at an outer end  36  opposite an inner end  38  anchored to the unit  18 . Each rail  34  accordingly extends in angular relation to the axis  40  of the shaft  12  radially spaced therefrom by an increasing amount from the anchored rail ends  38  to the opposite rail ends  36  at which the actuator devices  30  are adjustably positioned by adjustment devices  50  along an axial end section  42  of a peripheral gear  44  connected to the shaft end section  26 . Projecting from each of the cylindrical actuator devices  30  is a driving push rod  46 , for engagement with the periphery of the gear  44  along its axial end section  42  so as to impart a continuously varying output torque to the output shaft  12   
   As shown in  FIGS. 1 and 3 , the actuator units  28  may be axially displaced on its support  32  from an axial position  31 ( a ) at the end  36  of its rail  34  as designated in  FIG. 3  to two other axial positions  31 ( b ) and  31 ( c ) along the axial end section  42  of the gear  44  so as to effect a change in stroke of the drive forces applied to shaft  12  by the actuator driven push rods  46  dependent on the variation in peripheral diameter of the gear  44  along the end section  42 . Such repositioning of the actuator units  28  on the rails  34  is effected by the positioning adjustment devices  50  respectively mounted on each of the rails  34  and connected to the actuator unit supports  32 . 
   With continued reference to  FIG. 3 , the unit  18  is shown positioned on an intermediate larger diameter hollowed section  52  of the shaft  12  extending between the shaft end sections  20  and  26 . The unit  18  includes an outer cylindrical housing  54  positioned on the section  52  in abutment with the thrust bearing component  22  at one axial end opposite its other axial housing end plate  56 . The ends  38  of the rails  34  are anchored to the housing end plate  56 . The housing  54  is fixedly anchored in position on the shaft section  52  for rotational support of the shaft  12  which is rotated relative to the housing  54  about its axis  40 . Enclosed within the housing  54  are chambers  58  filled with a magneto-reheological fluid in surrounding relation to the shaft section  52  which is peripherally formed with splines  60  through which a pair discs  62  within the chambers  58  are positioned rotationally fixed to the shaft  12  by the shaft section  52 . An electromagnetic coil  64  is also positioned within the housing  54  overlying a pair of permanent magnets  55 , to partially or fully negate the braking effect thereby applied to the shaft  12  by the magnetic fields of the magnets  55  for free wheeling purposes. The magneto-rheological fluid filing the chamber  58  within such magnetic fields provides variable braking resistance to rotation of the shaft  12  through the discs  62 . 
   As diagrammed in  FIG. 4 , an electrical power source  64  supplies electrical energy through timing phase control  66  to one pair of the four actuator devices  30  associated with the drive torque imparting assembly  24  from which the generated drive forces are transferred through the gear  44  as torque applied to the output shaft  12 . The pair of the actuator devices  30  selected for imparting torque are aligned with each other along a diagonal line  67  as indicated in  FIG. 2 . The electrical energy from the source  64  is also supplied through control  66  to the positioning devices  50  for adjustable displacement of the drive torque imparting assembly  24  between its positions  31 ( a ),  31 ( b ) and  31 ( c ) for stroke change purposes. Finally, through the free-wheel control  68 , electrical energy from the source  64  is applied to coil  62  in the unit  18  during power-off phase of operation with respect to drive of the output shaft  12  by the actuators  30 , for free-wheeling purposes. 
   Obviously, other modifications and variations of the present invention may be possible in light of the foregoing teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.