Linear Stepper Motor Structure for Self-Locking Bionic Fingers

Solution Overview

Problem

Existing bionic dexterous hands face issues with poor transmission efficiency, positioning accuracy, and low output power due to continuous power requirements for maintaining grasping posture, along with poor space utilization.

Innovation Solution

A linear stepper motor with self-locking performance and higher transmission efficiency is integrated into the bionic finger, featuring a compact structure and improved space utilization, utilizing a stator, rotor, and lead screw mechanism to convert rotational power into linear motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a single motor drives multiple knuckles to rotate through a tendon rope, then the grasping action is achieved, but the transmission efficiency and positioning accuracy deteriorate

Engineering Contradiction:

Improvegrasping action capabilityVSAvoidtransmission efficiency

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

The patent divides the grasping mechanism into multiple independent linear stepping motors, with each motor independently driving one knuckle. This segmentation eliminates the need for tendon rope transmission, directly improving transmission efficiency and positioning accuracy while maintaining grasping functionality.

Inventive Principle:

Principle #1Segmentation

2Productivity

If a single motor drives multiple knuckles to rotate through a tendon rope, then the grasping action is achieved, but the positioning accuracy deteriorates

Engineering Contradiction:

Improvegrasping action capabilityVSAvoidpositioning accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent divides the grasping mechanism into multiple independent linear stepping motors, with each motor independently driving one knuckle. This segmentation eliminates the need for tendon rope transmission, directly improving transmission efficiency and positioning accuracy while maintaining grasping functionality.

Inventive Principle:

Principle #1Segmentation

3Stability of the object's composition

If continuous power is input to the motor to maintain grasping posture, then the grasping posture is maintained, but the space utilization and output power deteriorate

Engineering Contradiction:

Improvegrasping posture maintenanceVSAvoidspace utilization

Core Design Contradiction:

Stability of the object's compositionVSVolume of stationary object

Solution Approach 1:

The linear stepping motor incorporates a self-locking mechanism that automatically maintains the grasping posture without requiring continuous power input. The motor locks itself in position, eliminating the need for continuous energy consumption and reducing the overall system size and weight.

Inventive Principle:

Principle #25Self-service

4Stability of the object's composition

If continuous power is input to the motor to maintain grasping posture, then the grasping posture is maintained, but the output power deteriorates

Engineering Contradiction:

Improvegrasping posture maintenanceVSAvoidoutput power

Core Design Contradiction:

Stability of the object's compositionVSPower

Solution Approach 1:

The linear stepping motor incorporates a self-locking mechanism that automatically maintains the grasping posture without requiring continuous power input. The motor locks itself in position, eliminating the need for continuous energy consumption and reducing the overall system size and weight.

Inventive Principle:

Principle #25Self-service

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 linear stepper motor enhances grasping action control with high-speed and high-precision, maintaining grasping posture without continuous power input, increasing output power and stability.

Implementation Method 1

The stator drives the rotor and the drive nut to rotate together after being energized

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

The drive nut is threadedly connected to the lead screw, and the stator drives the rotor and the drive nut to rotate together after being energized so as to drive the lead screw to linearly project and retract

Methodology Applied

Scientific EffectThreaded connection mechanism: Screw

Data Source

PatentEP4718689A1Linear stepping motor, bionic finger and bionic dexterous hand

Publication Date: 2026.04.01 SHENZHEN ZHAOWEI MACHINERY&ELECTRONICS CO LTD

Figure 1

AI summary

Provided are a linear stepper motor, a bionic finger, and a bionic dexterous hand. The linear stepper motor includes an outer housing (10) and the following components disposed within the outer housing (10). The following components includes: a stator (6) fixed to an inner wall of the outer housing (10); a drive nut (1) rotatably disposed within the outer housing (10) and disposed to pass through an inner ring of the stator (6); a rotor (7) disposed around an outer peripheral portion of the drive nut (1); and a lead screw (2) slidably disposed in the outer housing (10) in an axial direction of the outer housing (10), where an end of the lead screw (2) is configured to extend out from the outer housing (10), the drive nut (1) is threadedly connected to the lead screw (2), and the stator (6) drives the rotor (7) and the drive nut (1) to rotate together after being energized, to drive the lead screw (2) to linearly project and retract relative to the outer housing (10).