Drive Unit for Robotic Manipulators

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.

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.