Surgical Drive Unit Segmented Stator Rotor Sealing

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Solution Overview

Problem

Current surgical power tools face challenges in easy cleaning and maintenance due to complex designs that expose mechatronic components to sterilization, making them difficult to clean and maintain effectively.

Innovation Solution

A drive unit for surgical power tools is designed with a simplified structure comprising two assemblies (stator and rotor) that can be easily dismantled, featuring hermetically sealed housings without external electrical connections, allowing for efficient cleaning and maintenance, and an integrated energy supply unit that can be quickly replaced.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the drive unit uses a complex design with multiple components and openings for cables, then it can achieve functional requirements, but it becomes difficult to clean and maintain

Engineering Contradiction:
Improveease of cleaningVSAvoidstructural complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The drive unit is divided into two separable assemblies: a stator assembly and a rotor assembly. This segmentation allows each assembly to be independently removed, cleaned, and sterilized without disassembling the entire drive unit, significantly simplifying maintenance while maintaining functional complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power supply unit is extracted from the rotor assembly and integrated into the stator assembly. This extraction eliminates the need for through-holes in the rotor housing for power cables, allowing the rotor to be completely sealed and easily sterilized by autoclaving.

Inventive Principle:
Principle #2Taking out (Extraction)

2Use of energy by moving object

If the stator housing has openings for electrical cables, then power can be supplied to the motor, but cleaning becomes difficult

Engineering Contradiction:
Improvepower supplyVSAvoidease of cleaning
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The drive unit is segmented into stator and rotor assemblies that can be separated. The power supply is located in the stator assembly which can be opened for cable access, while the rotor assembly remains sealed and cable-free for easy cleaning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power supply unit is extracted from the rotor and placed in the stator. This allows all electrical connections to be concentrated in the stator assembly, leaving the rotor assembly completely sealed without cable openings.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If mechatronic components are exposed to sterilization, then surgical sterility is achieved, but the components become difficult to maintain

Engineering Contradiction:
Improvesterilization capabilityVSAvoidmaintenance difficulty
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The drive unit is divided into separable stator and rotor assemblies. The rotor assembly can be completely removed and autoclaved as a single unit, achieving surgical sterility. If electronic components in the stator fail, the entire stator assembly can be replaced without complex disassembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The power supply and electronic control components are extracted from the rotor and placed in the stator assembly. This separation allows the rotor to be fully sterilizable while concentrating all non-sterilizable electronic components in the stator, which can be replaced as a unit if needed.

Inventive Principle:
Principle #2Taking out (Extraction)

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 design facilitates easy cleaning and maintenance, reduces the risk of defects by shielding components from aggressive media, and enables quick replacement of faulty parts, ensuring a low failure rate and efficient sterilization processes.

Implementation Method 1

The stator (4) comprises a hermetically sealed stator housing (10) and the rotor (5) comprises a rotor housing (21) which forms a hermetically sealed enclosure for the electrical rotor windings (11)

Methodology Applied
Scientific EffectHermetic sealing: Physical Containment

Data Source

PatentEP3844859B1Drive unit for a surgical power tool
Publication Date: 2022.10.05 SMC INNOVATION GMBH
  • EP3844859B1 patent drawingFigure 1
  • EP3844859B1 patent drawingFigure 2
  • EP3844859B1 patent drawingFigure 3

AI summary

The invention relates to a drive unit (1) for a surgical power tool, wherein the drive unit comprises an electric motor (2), which has a longitudinal axis (13), a housing (3), a stator (4) and a rotor (5). The rotor (5) comprises a rotor shaft (7) having a free end (6) and a surgical tool or a surgical device can be coupled to the free end (6). The drive unit also comprises a control system (9) for the electric motor (2). The stator (4) comprises a stator housing (10) and can be removed in its entirety from the electric motor (2), or installed therein. The drive unit (1) additionally comprises an energy supply unit (8) for the electric motor (2) and the control system (9) and the energy supply unit (8) and the control system (9) are arranged in the stator housing (10).