Dual-Reduction Quasi-Quasi-Direct Drive Joint Actuator for Robotic Limbs
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Solution Overview
Problem
Robotic systems face limitations in consumer applications due to overdesign and high costs of traditional high-reduction servo motors and quasi-direct-drive (QDD) motors, which result in bulky, aesthetically unpleasing, and space-intensive designs with extensive wiring requirements, lacking the necessary torque density and precision for human-like movements.
Innovation Solution
The development of a dual-reduction quasi-quasi-direct-drive (QQDD) joint actuator with a low-profile mounting base and wire pass-through design, offering a balance between reduction range and power density, reducing size and wiring needs, and enabling in-line joint configurations that are more human-like and aesthetically appealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional high-reduction servo motors or QDD motors are used, then torque density and precision are improved, but device size and wiring complexity increase
Solution Approach 1:
The patent segments the motor assembly into modular components: a motor housing containing the motor and encoder, a separate gearhead with reduction gears, and a coupling mechanism. This segmentation allows independent optimization of each component and simplifies wiring by consolidating electrical connections within the motor housing while mechanical connections are externalized through the gearhead interface.
Solution Approach 2:
The patent implements nesting by placing the encoder within the motor housing, and the gearhead reduction mechanism nested within the actuator assembly. The wire pass-through feature allows wiring to be nested within the motor housing structure rather than externally routed, reducing overall wiring complexity while maintaining precision measurement capabilities.
2Force
If traditional high-reduction servo motors or QDD motors are used, then torque density is improved, but device size and mounting space increase
Solution Approach 1:
The patent transitions from traditional lateral or top mounting configurations to a low-profile mounting arrangement where the actuator is mounted beneath the surface. This dimensional change allows the actuator to protrude minimally while maintaining high torque density through the nested gearhead reduction mechanism, significantly reducing the mounting footprint on the surface.
Solution Approach 2:
The gearhead reduction mechanism is nested within the actuator housing, allowing the high-torque-density components to be compactly arranged. The wire pass-through feature further utilizes the internal volume of the motor housing, eliminating the need for external wire routing channels and reducing the overall actuator envelope dimensions.
3Power
If traditional motors are used, then power density is maintained, but aesthetic appeal and consumer suitability deteriorate
Solution Approach 1:
By mounting the actuator low-profile beneath the surface rather than having it protrude or be externally mounted, the visible portion of the device is minimized. This dimensional arrangement conceals the mechanical components while maintaining power density internally, resulting in a cleaner, more aesthetically pleasing appearance suitable for consumer applications.
Solution Approach 2:
The patent extracts the wiring from the external environment and routes it through the motor housing via the wire pass-through feature. This extraction of wiring from the visible exterior to the internal structure eliminates visual clutter and creates a cleaner aesthetic appearance while maintaining full electrical connectivity for the power-dense motor components.
4Reliability
If extensive wiring is used, then electrical connectivity is ensured, but safety hazards and exposed wiring increase
Solution Approach 1:
The patent extracts the wiring from the external environment and routes it through the motor housing via the wire pass-through feature. This extraction of wiring from the visible exterior to the internal structure eliminates visual clutter and creates a cleaner aesthetic appearance while maintaining full electrical connectivity for the power-dense motor components.
Solution Approach 2:
The motor housing acts as an intermediary structure that provides a protected pathway for electrical wiring. The wire pass-through feature serves as a controlled interface between the internal motor components and external wiring, allowing electrical connectivity while shielding the wiring from environmental hazards and reducing safety risks from exposed conductors.
Data Source
AI summary
An apparatus for a robotic limb includes one or more limb segments connected via one or more joints. The robotic limb may feature one or more dual-reduction quasi-quasi-direct-drive joint actuators that permit the robotic limb to move throughout a scene. The robotic limb may further include an end-effector connected to a free end of the robotic limb with one or more opposable fingers comprising a four bar linkage. The end-effector may include a main actuator that actuates the one or more fingers via the four-bar linkages to complete various tasks.