Hollow Robot Joint Layout With Separate Brake for Compact Arms
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Solution Overview
Problem
Existing robot joint structures face challenges in minimizing size and weight due to the integration of motors with built-in brakes, which occupy significant space and increase outer dimensions, hindering the compactness and efficiency of robotic systems.
Innovation Solution
A robot joint structure featuring a hollow first and second member configuration with a motor-actuator system that includes a speed reducer and a separate brake mechanism, allowing for compact placement and reduced outer dimensions by separating the motor and brake components, enabling efficient rotation and braking without overlapping with the hollow section and center hole.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a motor with a built-in brake is used, then the braking function is integrated, but the size and weight of the joint structure increase
Solution Approach 1:
The brake mechanism is separated from the motor and positioned in the hollow section of the arm. The motor (40) and brake mechanism (50) are independently disposed at different positions, with the brake mechanism located in the hollow section (33) of the speed reducer. This segmentation allows the braking function to be integrated into the overall joint structure without increasing the motor size or adding external components, thereby maintaining compactness while achieving functional integration.
2Device complexity
If a motor with a built-in brake is used, then the braking function is integrated, but the outer dimensions of the arm increase
Solution Approach 1:
The brake mechanism is nested within the hollow section of the arm structure. Specifically, the brake mechanism (50) is disposed in the hollow section (33) of the speed reducer, which is already part of the arm's internal structure. The brake shaft (51) and brake body (53) are arranged to fit within the existing hollow space, utilizing the internal volume without increasing the outer diameter of the arm. This nesting approach allows functional integration while maintaining compact external dimensions.
3Length of stationary object
If the brake mechanism is placed in the hollow section, then the outer dimensions are reduced, but the gear engagement space becomes constrained
Solution Approach 1:
The gear engagement is arranged in a spatial configuration that utilizes the three-dimensional space within the hollow section. The third gear (52) is disposed at the brake shaft (51), and its engagement with the second gear (32) is arranged to occur within the available space of the hollow section (33). The axial and radial positions of the gears are optimized to ensure proper meshing while accommodating the brake mechanism, effectively utilizing spatial arrangement to resolve the constraint on gear engagement space.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration minimizes the internal and outer dimensions of the second arm, allowing for a more compact and lightweight robotic system by effectively utilizing internal space and reducing the outer diameter of the arm and wrist unit, thereby enhancing the overall size and weight reduction of the robot.
Implementation Method 1
a brake mechanism capable of braking rotation of the second member relative to the first member
Data Source
AI summary
A robot joint structure includes a first member and a second member that are hollow, an actuator that rotates the second member about a fourth axis relative to the first member, and a brake mechanism capable of braking rotation of the second member relative to the first member. The actuator includes a motor accommodated within the first member, a speed reducer that reduces the speed of rotation of a motor shaft of the motor and that transmits the rotation to the second member, a first gear provided at the motor shaft, and a second gear provided in the speed reducer and engaged with the first gear. The brake mechanism includes a brake body accommodated within the first member, a brake shaft capable of being braked by the brake body, and a third gear provided at the brake shaft and engaged with the second gear.