Robot Arm Driving Apparatus with Nested Transmission Paths
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Solution Overview
Problem
Existing robot arm driving systems require two electric motors to achieve two-axis movement, increasing the weight of the arm and reducing its exercise performance due to the motors being positioned on the arm itself.
Innovation Solution
The arm driving apparatus positions two electric motors closer together on the robot's body by using a driving source unit with four electric motors and four transmission paths, allowing the arm to move in four directions while reducing the weight of the arm by positioning the motors collectively on the robot's body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If two electric motors are provided on the arm to enable two-axis movement, then the arm can move in multiple directions, but the weight of the arm increases and exercise performance deteriorates
Solution Approach 1:
The electric motors are extracted from the arm and relocated to the robot's body. The patent configures the driving source unit with multiple electric motors on the body side, connected to the arm through transmission paths. This extraction removes the heavy motors from the moving arm portion, significantly reducing arm weight while preserving multi-axis movement capability through the transmission mechanism.
Solution Approach 2:
A transmission mechanism acts as an intermediary between the motors on the body and the arm joints. The patent employs transmission paths including gears, shafts, and connection units that transfer rotational motion from the motors to the arm's joint rotation members, enabling remote actuation without direct motor mounting on the arm.
2Weight of moving object
If two electric motors are positioned on the robot's body to reduce arm weight, then arm exercise performance improves, but the device complexity increases
Solution Approach 1:
Multiple electric motors are merged into a single integrated driving source unit on the robot's body. The patent combines the motor housings, transmission components, and control elements into one consolidated unit, which simplifies the overall system architecture despite the presence of multiple motors, and facilitates easier maintenance and manufacturing.
Solution Approach 2:
The transmission mechanism is designed with multi-functional components that can serve multiple purposes. For example, the connection units and joint rotation members are configured to handle both transmission and positioning functions, reducing the need for separate dedicated components and thereby lowering overall system complexity.
3Ease of operation
If electric motors are disposed on the arm, then direct actuation is achieved, but high force is required to move the arm due to increased weight
Solution Approach 1:
The motors are extracted from the arm and placed on the body, eliminating the need for high torque at the arm joints. This extraction reduces the moment of inertia and gravitational load that the motors would need to overcome, significantly lowering the torque requirements while maintaining direct actuation through the transmission paths.
Data Source
AI summary
A first transmission path includes a joint rotation member (13A) provided in a joint (J1) of an arm (Ar) and rotatable around a first axial line (Ax1), and a connection shaft portion (14A) that transmits rotation of an electric motor (11A) to the joint rotation member (13A). A second transmission path includes a joint gear (13B) provided in the joint (J1) of the arm (Ar) and rotatable around the first axial line (Ax1), and a connection shaft portion (14B) that transmits rotation of another electric motor (11B) to the joint gear (13B). Both of the connection shaft portion (14A) and the connection shaft portion (14B) are rotatable around the first axial line (Ax1), and the connection shaft portion (14B) is disposed on the inner side of the connection shaft portion (14A). The joint gear (13B) is kept in engagement with a joint gear (15B) rotatable around a second axial line (Ax2) intersecting with the first axial line (Ax1). According to this structure, two movements of the arm (Ar) are permitted, and besides the exercise performance of the arm (Ar) can be improved.