Compliant Pinion Drive for Smooth Rack Meshing in Climbing Robots

Solution Overview

Problem

Pinion gears on mobile robots in automated order fulfillment systems often fail to mesh properly with gear racks, leading to jamming and improper engagement during vertical travel.

Innovation Solution

A compliant pinion drive system with chamfered gear teeth and rotational play between splines to facilitate smooth meshing with gear racks, preventing jamming during vertical climbing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the pinion gear is extended axially to engage the rack, then vertical travel is enabled, but the pinion gear may jam against the rack and fail to mesh properly

Engineering Contradiction:

Improveengagement reliabilityVSAvoidjamming

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The chamfered lead-in portions are provided on the pinion gear teeth before engagement with the rack. These pre-formed chamfers guide the teeth into proper alignment as the pinion extends axially, preventing jamming by ensuring the teeth engage smoothly with the rack teeth from the initial contact point.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The spline connection between the shaft and pinion gear is designed with intentional play or clearance, allowing relative movement between these components. This parameter change enables the pinion gear to self-align and rotate slightly during axial extension, facilitating proper meshing with the rack while preventing jamming.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If the shaft is extended to position the pinion gear for meshing engagement, then vertical climbing is enabled, but improper meshing may occur causing the robot to fail to engage the rack

Engineering Contradiction:

Improveengagement smoothnessVSAvoidmeshing engagement

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The chamfered lead-in portions are provided on the pinion gear teeth before engagement with the rack. These pre-formed chamfers guide the teeth into proper alignment as the pinion extends axially, preventing jamming by ensuring the teeth engage smoothly with the rack teeth from the initial contact point.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The spline connection between the shaft and pinion gear is designed with intentional play or clearance, allowing relative movement between these components. This parameter change enables the pinion gear to self-align and rotate slightly during axial extension, facilitating proper meshing with the rack while preventing jamming.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20260062215A1Climbing robot with compliant pinion drive

Publication Date: 2026.03.05 SYMBOTIC LLC

AI summary

An automated order fulfillment system and mobile robot are disclosed, where the mobile robot includes a compliant drive for moving between levels of a multilevel storage structure.