Drive Unit for Robotic Manipulators

Abstract

In one form there is disclosed an internally balanced involute-type speed reducer; the reducer comprising a stator stage, an input stage, an output stage, and a plurality of gear sets in mesh. In a further form there is disclosed an actuator assembly for a robot; said actuator assembly comprising a stator core located within an outer housing and subtended by inner and outer mounting hubs; said hub supporting a drive train and bearings within the actuator assembly. In a further form there is disclosed a transducer system operable in conjunction with the reducer or actuator assembly.

What is claimed is: 
     
         1 . An extendable apparatus for articulation comprising:
 an outer housing with matching mounting hub interfaces at each end;   an inner hollow core with matching mounting hub interfaces at each end;   bearings between outer and inner hubs located one at each end; and   one or more actuation feature slices.   
     
     
         2 . The extendable apparatus for articulation as in  claim 1 , further comprising 
 an out runner frameless electric motor actuation feature slice providing direct drive actuation of the outer housing relative to the inner hollow core;
 the particular actuation feature slice comprising:
 an electric motor stator fixed to the inner hollow core; and 
 an electric motor rotor fixed to the outer housing. 
 
   
     
     
         3 . The extendable apparatus for articulation as in  claim 2 , further comprising
 a transmission actuation feature slice consisting of:
 a sunless, single compound pinion planetary gear transmission actuation feature to provide a torque and/or a motion reduction actuation feature of the outer housing relative to the motor rotor, the actuation feature comprising:
 a stator stage; a compound pinion; 
 a dual role motor and transmission rotor with offset crank; 
 an output stage, the actuation feature more specifically comprising: 
 a dual role integrated motor rotor and transmission rotor which is rotatably connected to the inner hollow core and includes an offset crank with an offset crank axis of rotation parallel to the central axis and is offset by a distance of the crank offset; 
 a compound pinion rotatably connected to the rotor offset crank which includes a primary row and an output row of many gear teeth that mesh with ring gear and output gear where their pitch circles intersect at only one point per mesh; 
 an output ring gear fixedly connected to the outer housing and with axis intersecting the central rotor axis comprises a plurality of gear teeth distributed evenly about the central axis which are in constant mesh with the output gear row of gear teeth of the compound pinion; 
 a stator ring gear fixedly connected to a hollow stator core, the stator ring gear has a primary row of many gear teeth distributed evenly about the central axis; and 
 a rotor offset crank distance set such that the gear teeth of the compound pinion are held in constant mesh with those of the stator ring gear and output ring gear where rotor rotation causes precession of the compound pinion around the stator ring gear and the output ring gear resulting in a torque and velocity differential between the rotor and the output ring gear. 
 
   
     
     
         4 . The extendable apparatus for articulation as in  claim 3 , wherein the transmission actuation feature is 
 a sunless, single internal compound pinion planetary gear transmission wherein
 the compound pinion gear teeth extend from the outer pinion surface and project outwards; 
 the teeth of output ring gear extent from the inner surface of the ring gear and project inwards; and 
 the stator ring gear teeth extend from the inner surface of the stator ring gear and projecting inwards. 
   
     
     
         5 . The extendable apparatus for articulation as in  claim 3 , wherein the transmission actuation feature is 
 a sunless, single external compound pinion planetary gear transmission wherein 
 the teeth of output ring gear extend from the outer surface of the gear and project outwards; 
 the teeth of stator ring gear extend from the outer surface and project outwards; 
 the compound pinion output row of gear teeth extend from the inner pinion surface and project inwards; and 
 the stator row of gear teeth extend from the inner pinion surface and project inwards. 
   
     
     
         6 . The extendable apparatus for articulation as in  claim 3 , wherein the transmission actuation feature is 
 a sunless, single hybrid compound pinion planetary gear transmission wherein
 the teeth of output ring gear extend from the inner surface of the gear and project inwards; 
 the teeth of stator ring gear extend from the outer surface and project outwards; 
 the compound pinion output row of gear teeth extend from the outer pinion surface and project outwards; and 
 the stator row of pinion gear teeth extend from the inner pinion surface and project inwards. 
   
     
     
         7 . The extendable apparatus for articulation as in  claim 3 , wherein the transmission actuation feature is 
 a sunless, single inline compound pinion planetary gear transmission wherein 
 the teeth of output ring gear 1 extend from the inner surface and project inwards; 
 the teeth of stator ring gear extend from the outer surface and project outwards; 
 the compound pinion output row of gear teeth extend from the outer pinion surface and project outwards; and 
 the stator row of gear teeth extends from an internal surface and project inwards. 
   
     
     
         8 . The extendable apparatus for articulation of  claim 1 , further comprising
 an instrumentation and/or controller actuation feature normal to central axis of rotation comprising:
 a PCB incorporating instrumentation and or controller actuation features positioned between the upstream inner mounting hub and the motor stator windings; and 
 one or more cable looms for connection of the instrumentation and or controller actuation feature to external equipment. 
   
     
     
         9 . The extendable apparatus for articulation of  claim 3 , further comprising
 a series elastic actuation feature slice, the actuation feature slice comprising:
 a spring element connected at one end to the inner hollow core and connected at its other end to the stator ring gear; and 
 a stator ring gear bearing providing free rotation and alignment of the stator ring gear relative to the outer housing. 
   
     
     
         10 . The extendable apparatus for articulation of  claim 2 , wherein
 the electric motor is an in runner electric motor comprising:
 an electric motor stator fixed to the outer housing; and 
 an electric motor rotor fixed to the inner hollow core. 
   
     
     
         11 . The extendable apparatus for articulation of  claim 2 , wherein the extendable apparatus for articulation is a robot apparatus. 
     
     
         12 . A universal articulation apparatus comprising
 an outer housing with matching mounting interfaces at each end rotatably connected to an inner hollow core with matching mounting interfaces at each end, constituting:
 an outer housing providing housing and peripheral surface attachment interfaces; 
 outer hub rings (upstream end) and (downstream end) providing attachment interfaces at each end which are fixedly attached to the outer housing; 
 an inner hollow core providing end to end line routing, fixedly connected to inner mounting hubs providing attachment interfaces known in the art at each end; 
 bearings incorporated between the inner and outer mounting hubs at each end supporting axial rotation; 
 instrumentation and or controller located downstream from a hollow stator hub which extends the inner hollow core and outer housing to accommodate instrumentation and or controls; 
 a motor actuation feature located downstream from the hollow stator hub and any previous upstream slices extending the inner hollow core and outer housing to accommodate a motor stator fixedly connected to the inner hollow core; 
 a motor rotor fixedly connected to the offset crank; 
 a transmission actuation feature normal to central axis of rotation downstream from the hollow stator hub consisting of a sunless, single compound pinion planetary gear transmission the transmission comprising:
 a stator stage, an input rotor stage, an output stage, and a plurality of gear sets, the transmission constituting: 
 a dual role motor and transmission rotor which is rotatably connected to the inner hollow core and receives rotation from any upstream drive train actuation features and includes an offset crank with an offset crank axis of rotation parallel to the central axis and is offset by a distance of the crank offset and includes a counterweight fixedly connected to the rotor which is located such that it balances both the motor rotor and the transmission; 
 a compound pinion rotatably connected to the rotor offset crank includes a primary row and an output row of many gear teeth that mesh with ring gear and output gear where their pitch circles intersect at only one point per mesh; 
 an output ring gear fixedly connected to the outer housing and with axis intersecting the central rotor axis comprises a plurality of gear teeth distributed evenly about the central axis which are in constant mesh with the output gear row of the compound pinion, rotation of which induces rotation of the output ring gear relative to the rotor rotation with gear ratio set by difference between the reduction ratio of the primary pinion and stator ring gear and the reduction ratio of the secondary pinion gears and output ring gear; 
 a stator ring gear fixedly connected to a hollow stator core, the stator ring gear has a primary row of many gear teeth distributed evenly about the central axis; and 
 a rotor offset crank distance set such that the gear teeth of the compound pinion are held in constant mesh with those of the stator ring gear and output ring gear where rotor rotation causes precession of the compound pinion around the stator ring gear and the output ring gear resulting in a torque and velocity differential between the rotor and the output ring gear. 
 
   
     
     
         13 . The universal articulation apparatus of  claim 12 , configured as a stiff servo, wherein the transmission slice is 
 a sunless, single internal compound pinion planetary gear transmission wherein;
 the compound pinion gear teeth extend from the outer pinion surface and project outwards; 
 the teeth of output ring gear extent from the inner surface of the and project inwards; and 
 the stator ring gear teeth extend from the inner surface of the stator ring gear and projecting inwards. 
   
     
     
         14 . The universal articulation apparatus of  claim 12 , configured as a stiff servo wherein the transmission slice is 
 a sunless, single external compound pinion planetary gear transmission wherein
 the teeth of output ring gear extend from the outer surface of the gear and project outwards; 
 the teeth of stator ring gear extend from the outer surface and project outwards; 
 the compound pinion output row of gear teeth extend from the inner pinion surface and project inwards; and 
 the stator row of gear teeth extend from the inner pinion surface and project inwards. 
   
     
     
         15 . A universal articulation apparatus comprising
 an outer housing rotatably connected to an inner hollow core, with mounting interfaces peripherally and at each end;   the articulation characteristics are extendable via the addition of actuation features normal to central axis of rotation;   the actuation features hubs, bearings, motors, transmissions, springs, instrumentation and controllers constituting:
 an outer housing providing housing and peripheral surface attachment interfaces; 
 outer hub rings (upstream end) and (downstream end) providing attachment interfaces known in the art at each end which are fixedly attached to the outer housing; 
 an inner hollow core providing end to end line routing, fixedly connected to inner mounting hubs providing attachment interfaces known in the art at each end; 
 bearings incorporated between the inner and outer mounting hubs at each end supporting axial rotation; 
 an includable instrumentation and or controls axial actuation feature slice located downstream from a hollow stator hub which extends the inner hollow core and outer housing to accommodate instrumentation and or controls; 
 an includable motor actuation feature normal to central axis of rotation located downstream from the hollow stator hub and any previous upstream slices extending the inner hollow core and outer housing to accommodate a motor stator fixedly connected to the inner hollow core; 
 a motor rotor fixedly connected to the input of any downstream drive train stages present or in the absence of other drive train stages to the outer housing; 
 an includable transmission actuation feature normal to central axis of rotation downstream from the hollow stator hub and any previous upstream slices extending the inner hollow core and outer housing to accommodate a further drive train feature consisting of a sunless, single compound pinion planetary gear transmission the transmission comprising; 
 a stator stage, an input rotor stage, an output stage, and a plurality of gear sets, the transmission constituting:
 a dual role motor and transmission rotor which is rotatably connected to the inner hollow core and receives rotation from any upstream drive train actuation features and includes an offset crank with an offset crank axis of rotation parallel to the central axis and is offset by a distance of the crank offset and includes a counterweight fixedly connected to the rotor which is located such that it balances both the motor rotor and the transmission; 
 a compound pinion rotatably connected to the rotor offset crank includes a primary row and an output row of many gear teeth that mesh with ring gear and output gear where their pitch circles intersect at only one point per mesh; 
 an output ring gear fixedly connected to the outer housing and with axis intersecting the central rotor axis comprises a plurality of gear teeth distributed evenly about the central axis which are in constant mesh with the output gear row of the compound pinion, rotation of which induces rotation of the output ring gear relative to the rotor rotation with gear ratio set by difference between the reduction ratio of the primary pinion and stator ring gear and the reduction ratio of the secondary pinion gears and output ring gear; 
 a stator ring gear fixedly connected to the input stage of any subsequent downstream drive train features or in their absence to a hollow stator core, the stator ring gear has a primary row of many gear teeth distributed evenly about the central axis; 
 a rotor offset crank distance set such that the gear teeth of the compound pinion are held in constant mesh with those of the stator ring gear and output ring gear where rotor rotation causes precession of the compound pinion around the stator ring gear and the output ring gear resulting in a torque and velocity differential between the rotor and the output ring gear; and 
 an includable spring actuation feature normal to central axis of rotation downstream from the hollow stator hub and any previous upstream slices extending the inner hollow core and outer housing to accommodate a further drive train feature consisting of a spring element receiving input rotation from the output of any upstream drive train actuation features, the spring is rotatably connected to the outer housing via bearing and is fixedly connected to the input of any downstream drive features or in the absence of these is fixedly connected to the hollow stator core, the spring provides an elastic drive train element functioning in series between upstream drive train features and downstream drive train features. 
 
   
     
     
         16 . The universal articulation apparatus of  claim 15 , configured as a slewing bearing. 
     
     
         17 . The universal articulation apparatus of  claim 15 , configured as a direct drive motor. 
     
     
         18 . The universal articulation apparatus of  claim 15 , configured as a stiff servo. 
     
     
         19 . The universal articulation apparatus of  claim 15 , configured as a stiff servo, wherein the transmission slice is
 a sunless, single internal compound pinion planetary gear transmission wherein
 the compound pinion gear teeth extend from the outer pinion surface and project outwards; 
 the teeth of output ring gear extent from the inner surface of the and project inwards; and 
 
 the stator ring gear teeth extend from the inner surface of the stator ring gear and projecting inwards. 
     
     
         20 . The universal articulation apparatus of  claim 15 , configured as a stiff servo, wherein the transmission slice is 
 a sunless, single external compound pinion planetary gear transmission wherein
 the teeth of output ring gear extend from the outer surface of the gear and project outwards; 
 the teeth of stator ring gear extend from the outer surface and project outwards; 
 the compound pinion output row of gear teeth extend from the inner pinion surface and project inwards; and 
 the stator row of gear teeth extend from the inner pinion surface and project inwards.