Surgical Robot Transmission Assembly for Compact Accurate Torque Transfer

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing minimally invasive surgical robots face issues with low transmission accuracy, poor loading conditions of transmission parts, inefficient space utilization, and maintenance challenges due to inadequate design in their transmission assemblies, leading to reduced performance and increased stress on components.

Innovation Solution

A transmission assembly with an input base, guide transmission, and output base, featuring an axial energy storage member and axial limiting assembly, which allows for improved torque transmission accuracy, reduced axial dimension, and easier assembly and maintenance, while preventing dust ingress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the circumferential limiting location is closer to the centerline of the shaft, then the structure is more compact, but the transmission accuracy decreases

Engineering Contradiction:
Improvestructural compactnessVSAvoidtransmission accuracy
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent moves the circumferential limiting location from the centerline to the outer circumferential surface of the shaft, utilizing the radial dimension to maximize the distance r. This dimensional change directly improves transmission accuracy by increasing the lever arm for torque transmission while maintaining structural compactness through optimized radial positioning.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the distance from the force-loaded surfaces to the center of rotation is shorter, then the structure is more compact, but the force loading condition deteriorates and stress increases

Engineering Contradiction:
Improvestructural compactnessVSAvoidforce loading condition
Core Design Contradiction:
Volume of moving objectVSStress or pressure

Solution Approach 1:

The patent positions the force-loaded surfaces at the outer circumferential surface of the shaft, utilizing the radial dimension to maximize the distance r from the center of rotation. This increases the moment arm for torque transmission, reducing the force F required to transmit a given torque M, thereby improving the force loading condition and reducing stress on transmission parts.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Length of moving object

If the axial dimension is reduced for miniaturization, then the device size is smaller, but the space utilization becomes insufficient

Engineering Contradiction:
Improveaxial dimensionVSAvoidspace utilization efficiency
Core Design Contradiction:
Length of moving objectVSProductivity

Solution Approach 1:

The patent introduces an axial energy storage member (spring) that enables dynamic axial movement of the output base relative to the input base. This dynamic mechanism allows the transmission assembly to achieve both compact axial dimension and efficient space utilization by allowing the output base to move axially during operation while maintaining a compact overall structure.

Inventive Principle:
Principle #15Dynamics

4Ease of manufacture

If the transmission assembly structure is simplified, then the manufacturing is easier, but the installation and maintenance convenience deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidinstallation and maintenance convenience
Core Design Contradiction:
Ease of manufactureVSEase of repair

Solution Approach 1:

The patent divides the transmission assembly into distinct modular components: an input base, an output base, and an axial energy storage member. This segmentation allows each component to be manufactured independently using standard processes while facilitating easy assembly and disassembly for installation and maintenance, as the modular components can be independently serviced or replaced.

Inventive Principle:
Principle #1Segmentation

5Ease of operation

If the transmission assembly is exposed for functionality, then the operation is more convenient, but dust ingress increases affecting movement smoothness

Engineering Contradiction:
Improveoperational accessibilityVSAvoiddust ingress
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a dust-proof cover that encloses the transmission assembly components. This cover acts as a protective barrier preventing dust and foreign matter from entering the clearances between moving parts, while still allowing the transmission assembly to function properly. The cover maintains operational accessibility while eliminating the harmful effect of dust ingress.

Inventive Principle:
Principle #30Flexible shells and thin films

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 solution enhances transmission accuracy, reduces stress on components, and facilitates miniaturization and maintenance, leading to improved performance and extended service life of surgical robots.

Implementation Method 1

an axial energy storage member configured to store energy during movement of the input base and the output base toward each other under the action of an external force and to release, upon removal of the external force, the energy to drive movement of the input base and the output base away from each other

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4085864B1Transmission assembly, drive box, surgical instrument system, and robot system
Publication Date: 2024.05.08 SHANGHAI MICROPORT MEDBOT (GRP) CO LTD
  • EP4085864B1 patent drawingFigure 1~2b
  • EP4085864B1 patent drawingFigure 3a~3d
  • EP4085864B1 patent drawingFigure 3e~3g

AI summary

A transmission assembly (1000), a drive box (100), a surgical instrument system and a surgical robot system are disclosed. The transmission assembly (1000) includes: an input base (1100) having a first end and an opposing second end, the first end connected to a drive mechanism (2000); a guide transmission (1200) disposed on an outer circumferential surface of the input base (1100); an output base (1300) having a third end and an opposing fourth end, the third end located proximal to the first end; an axial energy storage member (1400) configured to resist, when the input base (1100) and the output base (1300) are moving toward each other under the action of an external force, the movement of them toward each other and store energy and to release, upon removal of the external force, the energy to drive movement of the input base (1100) and the output base (1300) away from each other; and an axial limiting assembly configured to limit a maximum displacement of the input base (1100) and the output base (1300) from each other, wherein when the input base (1100) is driven by the drive mechanism (2000) to rotate, the guide transmission (1200) is configured to cause the output base (1300) to rotate in synchronization with the input base (1100).