2D Piezoelectric Table Layout Without Cable-Induced Position Error

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Solution Overview

Problem

Existing 2-dimensionally movable linear or rotary tables face challenges in achieving high positioning accuracy and movement linearity due to the disruption caused by connecting cables for piezoelectric linear drives, especially in applications requiring precise positioning in the nanometer range.

Innovation Solution

The introduction of a middle rotor plate between the stator and the upper rotor plate, with piezoelectric linear drives fastened to the stator and in contact with the upper rotor plate through an opening in the middle rotor plate, allowing independent movement of the upper rotor plate in two directions without a movable connecting cable, and the use of encapsulated piezoelectric linear drives to protect against environmental influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If connecting cables are used to supply the second piezoelectric linear drive, then the drive can be mounted on the movable middle slider plate, but the cable disrupts the movement of the middle slider plate and reduces positioning accuracy

Engineering Contradiction:
Improvemounting flexibility of piezoelectric linear driveVSAvoidpositioning accuracy of upper slider plate
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent extracts and removes the connecting cable from the system by mounting the second piezoelectric linear drive directly on the stator. This eliminates the cable that was disrupting the movement of the middle slider plate, thereby resolving the contradiction between mounting flexibility and positioning accuracy.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a middle slider plate as an intermediary component that enables the second piezoelectric linear drive to be mounted on the stator while still controlling the upper slider plate. The middle slider plate acts as a mediator that transmits the driving force without requiring a flexible cable connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If connecting cables are used for the second piezoelectric linear drive, then the drive can be positioned on the middle slider plate, but the cable stiffness influences movement linearity and positioning stability

Engineering Contradiction:
Improvepositioning capability in two independent directionsVSAvoidlinearity of movement of upper slider plate
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent removes the connecting cable from the system by mounting the second piezoelectric linear drive directly on the stator. This extraction eliminates the cable stiffness that was influencing movement linearity, thereby resolving the contradiction between positioning capability and movement linearity.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If piezoelectric linear drives are mounted on the movable slider plate, then the drive can move with the slider plate, but the connecting cable must move along with it which disrupts precise positioning

Engineering Contradiction:
Improvemobility of piezoelectric linear drive with slider plateVSAvoidpositioning precision in nanometer range
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent extracts the connecting cable from the system and mounts the second piezoelectric linear drive directly on the stator. This eliminates the cable that would have to move with the slider plate, thereby enabling precise positioning in the nanometer range.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical cable connection with a direct mounting configuration where the second piezoelectric linear drive is fixed on the stator. This substitution eliminates the mechanical disruption caused by cable movement while maintaining the mobility and control capabilities.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 achieves sub-nanometer positioning accuracy and maximum motion linearity with good long-term stability, ensuring precise and stable movement without cable interference, while encapsulation enhances the service life and reliability of the drives.

Implementation Method 1

at least two piezoelectric linear drives for moving the upper slider plate in the two translational directions or two rotational directions

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP4342065B12-dimensionally movable linear or rotary table
Publication Date: 2025.07.02 PHYSIK INSTRUMENTE (PI) GMBH & CO KG
  • EP4342065B1 patent drawingFigure 1~2(b)
  • EP4342065B1 patent drawingFigure 3(a)~5(b)
  • EP4342065B1 patent drawingFigure 6(a)~7

AI summary

The present invention relates to a linear or rotary table which can be moved in two dimensions, with a stator and at least one upper rotor plate which can be moved in two independent translational directions or two independent rotary directions with respect to the stator, and at least two piezo-electric linear drives for moving the upper rotor plate in the two translational or rotary directions. Here, a middle rotor plate is provided which is arranged between the stator and the upper rotor plate. The at least two piezo-electric linear drives are in each case fastened to the stator, in order to move the upper rotor plate in the two translational directions or two rotary directions. At least one piezo-electric linear drive which is fastened to the stator is in contact with the upper rotor plate through an opening in the middle rotor plate, in order to move the upper rotor plate in a first translational or rotary direction. The at least two piezo-electric linear drives are preferably configured as piezo-electric frictional contact drives.