Robot Wrist Mechanism With Encoder Braking for Precise Rotation
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Solution Overview
Problem
Conventional wrist units for industrial robots suffer from reduced transmission accuracy and increased size due to belt slippage and wear, affecting rotation precision and requiring larger structures.
Innovation Solution
A wrist mechanism with a housing unit, first and second rotation units, and brake units, utilizing encoders for closed-loop control and brake pads to stop rotation at desired positions, eliminating the need for belt pulleys and reduction devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If belt pulleys and belts are used for power transmission, then the mechanism can transmit power from motors to reduction devices, but transmission accuracy deteriorates due to belt slippage and wear
Solution Approach 1:
The patent removes the belt transmission components (belt pulleys and belts) from the wrist mechanism, directly connecting motors to reduction devices. This extraction eliminates the source of slippage and wear, ensuring direct and accurate power transmission from the first motor to the first reduction device and from the second motor to the second reduction device, thereby maintaining high transmission accuracy and rotation precision.
Solution Approach 2:
The patent replaces the belt-based mechanical transmission system with a direct mechanical connection system. Instead of using belts that can slip and wear, the motors are directly coupled to the reduction devices, eliminating the intermediate transmission elements that compromise accuracy. This substitution ensures reliable and precise power transmission throughout the mechanism's operation.
2Power
If belt pulleys and reduction devices are included, then power transmission is achieved, but the mechanism size increases
Solution Approach 1:
The patent extracts and removes the belt pulley components from the mechanism, eliminating unnecessary space-consuming elements. By directly mounting the first motor and second motor to their respective reduction devices without intermediate belt pulleys, the overall volume of the wrist mechanism is reduced while maintaining full power transmission capability through direct mechanical coupling.
3Power
If conventional wrist unit structures are used, then power transmission is achieved, but the structure becomes too complex and large
Solution Approach 1:
The patent extracts and removes the complex belt transmission subsystem including first belt pulley, second belt pulley, and belts from the conventional wrist unit structure. This simplifies the overall structure by eliminating intermediate transmission components, reducing the number of parts that need to be assembled, maintained, and aligned, while preserving the essential power transmission function through direct motor-to-reduction-device connections.
Solution Approach 2:
The patent merges the motor mounting and power transmission functions into a more integrated configuration. By directly coupling the motors to the reduction devices without separate belt pulley assemblies, the design combines multiple functions into fewer components, reducing structural complexity and improving the compactness of the wrist mechanism.
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
Enhances rotation accuracy and reliability while reducing the mechanism's size by using encoders for precise control and brake units to stop rotations, resulting in a compact design.
Implementation Method 1
The first encoder measures an angle of rotation of the first rotating shaft, and controls the first motor via closed-loop control
Implementation Method 2
The second encoder measures an angle of rotation of the second rotating shaft, and controls the second motor via closed-loop control
Implementation Method 3
When the first brake plate is urged to move along the first axis to abut against the first brake pad, the rotation of the first rotating shaft is stopped
Implementation Method 4
When the second brake plate is urged to move along the second axis to abut against the second brake pad, the rotation of the second rotating shaft is stopped
Data Source
AI summary
A wrist mechanism includes a first rotation unit, a second rotation unit, a first brake pad, and a first brake plate. The first rotation unit includes a first motor, a first rotating shaft that is connected to the first motor, and a first encoder. The first motor is operable to drive the first rotating shaft to rotate about a first axis. The first encoder measures an angle of rotation of the first rotating shaft. The second rotation unit is co-rotatable with the first rotating shaft about the first axis. The first brake pad is connected to the first rotating shaft. The first brake plate is operable to move relative to the first brake pad along the first axis. When the first brake plate is urged to move along the first axis to abut against the first brake pad, the rotation of the first rotating shaft is stopped.