Integrated Rotary Drive Assembly for Compact Robot Arm Joints

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Solution Overview

Problem

Existing rotary drive devices are not compact or weight-saving, making them less suitable for use in robot arms as arm joints, and they often require complex external fluid channel systems that are prone to damage.

Innovation Solution

A modular rotary drive device design that integrates a fluid-operated rotary drive with a control valve arrangement, pneumatic connection unit, and electronic control unit as a single self-supporting unit, featuring a control fluid channel system within the device and using piezoelectric or electromagnetic control valves for compactness and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fluid-operated rotary drive with external fluid hoses is used, then the rotary drive can be controlled for rotation and positioning, but the device becomes less compact and more prone to damage

Engineering Contradiction:

Improvedamage resistance of fluid channelsVSAvoidexternal fluid channel system

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the control fluid channel system directly into the drive housing, merging the previously external fluid channels with the main body. This eliminates vulnerable external connections and creates a compact, integrated structure where the control fluid channels are formed as integral parts of the drive housing, resolving the contradiction between reliability and device complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Weight of moving object

If traditional rotary drive designs are used, then the drive function is achieved, but the device is not compact and not weight-saving

Engineering Contradiction:

Improveweight of rotary drive deviceVSAvoidvolume of rotary drive device

Core Design Contradiction:

Weight of moving objectVSVolume of moving object

Solution Approach 1:

The patent combines multiple components (drive housing, control fluid channel system, pivot piston assembly) into a single integrated unit. This merging eliminates the need for separate external fluid channels and reduces the overall volume and weight of the rotary drive device while maintaining full drive functionality, directly addressing the contradiction between compactness and weight reduction.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The drive housing serves multiple functions simultaneously: it provides structural containment, houses the control fluid channel system, and supports the pivot piston assembly. This multi-functionality reduces the number of separate components needed, thereby reducing both weight and volume while achieving the same drive effect.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Volume of moving object

If modular integrated design is implemented, then compactness and weight reduction are achieved, but the device requires precise integration of multiple components

Engineering Contradiction:

Improvevolume of rotary drive deviceVSAvoidintegration precision of components

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

By forming the control fluid channel system as an integral part of the drive housing rather than a separate component, the patent eliminates the need for precise assembly between separate fluid channel parts and the housing. This merging reduces manufacturing precision requirements while achieving compact dimensions, resolving the contradiction between volume reduction and manufacturing precision.

Inventive Principle:

Principle #5Merging (Combining)

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 modular design results in a compact, weight-saving rotary drive device that is suitable for robot arms, with improved reliability and reduced risk of fluid channel damage, enabling precise rotational positioning and efficient force transmission.

Implementation Method 1

using piezoelectric or electromagnetic control valves for compactness and reliability

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

using piezoelectric or electromagnetic control valves for compactness and reliability

Methodology Applied

Scientific EffectElectromagnetic effect: Electromagnet

Implementation Method 3

fluid-actuated rotary drive, which has a drive housing and a drive unit rotatable relative thereto about a main axis of the rotary drive by a controlled fluid application of at least one pivot piston

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Data Source

PatentUS11007640B2Rotary drive device and a robot arm of a robot equipped therewith

Publication Date: 2021.05.18 FESTO AG & CO KG

AI summary

A rotary drive device has a fluid-actuated rotary drive, which has a drive housing and a drive unit rotatable relative thereto. The drive unit has a pivot piston and a drive shaft connected thereto, whereby the drive shaft projects from the drive housing on an axial front side with a drive section. On the rear side, several components are mounted in axial succession on the drive housing of the rotary drive, which together with the rotary drive form a uniformly practicable drive assembly. These components include a valve carrier device carrying a control valve arrangement, a pneumatic connection unit, and an electronic control unit electrically connected to the control valve arrangement. A robot arm is also proposed, which includes the rotary drive device as an arm joint.