Robot Joint Gear Layout for High Torque in Low Vertical Space
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Solution Overview
Problem
Existing workpiece transfer robots face challenges with large vertical dimensions and reduced torque due to the magnetic force of oscillating gears being insufficient and the difficulty in arranging electrical wiring and piping within the joint space.
Innovation Solution
A workpiece transfer robot design with a fixed gear, oscillating gear, and output gear arrangement around the output shaft, utilizing a permanent magnet and electromagnet configuration to minimize vertical dimension and enable efficient wiring and piping through a hollow output shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an oscillating gear mechanism with coils is used to achieve large reduction ratio, then the reduction ratio is increased, but the vertical dimension becomes large
Solution Approach 1:
The patent replaces the traditional coil-based electromagnetic drive with a permanent magnet synchronous motor. The permanent magnet rotor generates magnetic fields that interact with stator windings to produce rotational motion, eliminating the need for oscillating gears and coils while achieving the same drive function with a more compact structure
Solution Approach 2:
The patent repositions the speed reducer from a vertical arrangement to a horizontal arrangement. The bevel gears are positioned laterally around the output shaft rather than stacked vertically, transforming the spatial layout from vertical to horizontal and thereby reducing the vertical dimension of the joint
2Force
If magnetic force of oscillating gear is increased to improve torque, then torque is increased, but the structure becomes more complex
Solution Approach 1:
The patent replaces the oscillating gear mechanism with a direct-drive permanent magnet synchronous motor coupled to a speed reducer. This substitution eliminates the complex oscillating gear structure with teeth on both sides and the need for sequential coil energization, while providing more reliable torque through electromagnetic direct drive
Solution Approach 2:
The patent changes the drive mechanism from magnetic attraction via coils to electromagnetic induction via permanent magnets and stator windings. This parameter change in the electromagnetic system provides stronger and more controllable torque while simplifying the mechanical structure
3Length of stationary object
If the joint space is reduced to minimize size, then the vertical dimension is reduced, but wiring and piping become difficult to arrange
Solution Approach 1:
The patent repositions the speed reducer horizontally around the output shaft, creating lateral space for wiring and piping channels. This dimensional reorganization from vertical stacking to horizontal arrangement provides accessible pathways for electrical and pneumatic connections without increasing the vertical footprint
Solution Approach 2:
The patent segments the joint into functional zones: the permanent magnet synchronous motor section, the speed reducer section with lateral wiring channels, and the output shaft section. This segmentation allows wiring and piping to be routed through dedicated channels in the speed reducer housing, facilitating ease of installation and maintenance
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
The design achieves a large driving force while reducing the vertical dimension of the joint, allowing for improved transport accuracy and ease of electrical integration.
Implementation Method 1
an electromagnet provided in an internal space of a front end of the second arm side and generating a rotating magnetic field with respect to the permanent magnet
Implementation Method 2
When electricity is applied to one of the six coils k, the oscillating gear h is attracted by the magnetic field generated by that coil k
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
Provided is a workpiece transfer robot comprising a joint equipped with a highly precise actuator that has a small size in the vertical direction. The present invention is a workpiece transfer robot comprising a joint equipped with an actuator 1 configured from a speed reducer section and a motor section, wherein the speed reducer section is arranged parallel to a circular fixed gear 5 and a circular output gear 4, and an oscillating gear 6 is arranged inclined with respect to the fixed gear 5 and the output gear 4 between the fixed gear 5 and the output gear 4. The fixed gear 5 and the oscillating gear 6 are configured so as to mesh at a first position, and the oscillating gear 6 and the output gear 4 are configured so as to mesh at a second position. In addition, the motor section drives the oscillating gear 6 and is arranged coaxially with a permanent magnet 7 on the outside of the oscillating gear 6, and the size of the joint of the workpiece transfer robot in the vertical direction is minimized by arranging an electromagnet 28 coaxially on the outside of the permanent magnet.