Rack and Roller Pinion Lift System for Quiet Passenger Elevators
Solution Overview
Problem
Rack and gear elevators suffer from noise issues and poor ride comfort, making them unsuitable for non-industrial applications despite offering space efficiency and reduced infrastructure needs.
Innovation Solution
A rack and roller pinion lift system with parallel elongated racks, a drive unit, and a speed limiter, featuring roller pinions that minimize friction and provide mechanical advantage, along with a design that includes rounded teeth for reduced noise and increased strength, allowing for easier operation with minimal power requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a rack and gear system is used for elevation, then space efficiency is improved and infrastructure needs are reduced, but noise increases and ride comfort deteriorates
Solution Approach 1:
The patent replaces the traditional gear teeth engagement mechanism with a roller pinion system that rolls along the rack. This substitution transforms the sliding friction and impact-based mechanical interaction into a rolling contact system, significantly reducing noise generation while maintaining the compact space-efficient design of rack-based elevation systems
Solution Approach 2:
The roller pinion system employs periodic engagement and disengagement with the rack through a series of discrete rollers spaced along the pinion circumference. This periodic rolling contact creates smoother, quieter operation compared to continuous gear tooth sliding, as each roller makes brief contact and then rolls away, reducing impact noise and vibration
2Area of stationary object
If a rack and gear system is used for elevation, then space efficiency is improved, but ride comfort deteriorates
Solution Approach 1:
The patent replaces the traditional gear teeth engagement mechanism with a roller pinion system that rolls along the rack. This substitution transforms the sliding friction and impact-based mechanical interaction into a rolling contact system, significantly reducing noise generation while maintaining the compact space-efficient design of rack-based elevation systems
Solution Approach 2:
The roller pinion system employs periodic engagement and disengagement with the rack through a series of discrete rollers spaced along the pinion circumference. This periodic rolling contact creates smoother, quieter operation compared to continuous gear tooth sliding, as each roller makes brief contact and then rolls away, reducing impact noise and vibration
3Loss of energy
If roller pinions are used instead of gear teeth, then friction is minimized and mechanical advantage is improved, but device complexity increases
Solution Approach 1:
The pinion is segmented into multiple discrete rollers spaced around its circumference rather than using a single continuous gear structure. Each roller independently contacts the rack, distributing the mechanical load and reducing friction through rolling contact. This segmentation simplifies the manufacturing of individual roller components while achieving superior mechanical efficiency
Solution Approach 2:
The rollers act as intermediary elements between the pinion shaft and the rack. Instead of direct gear tooth engagement, the rollers mediate the force transmission by rolling along the rack surface, reducing friction and wear while maintaining mechanical advantage. This intermediary rolling contact simplifies the interaction mechanism compared to complex gear tooth geometry
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 system reduces noise and enhances ride comfort, enabling its use in non-industrial settings while maintaining space efficiency and lowering power requirements, thus making it suitable for applications like passenger elevators.
Implementation Method 1
Roller pinions are provided to smooth the action and minimize friction
Implementation Method 2
provide mechanical advantage for easy operation with minimal power requirements
Implementation Method 3
The speed limiter interacts with the rack to produce a slow descent
Data Source
AI summary
A lift system comprising an elongated rack and a roller pinion drive system. A preferred version has two parallel rack with plurality of rungs extending horizontally between the racks to form a ladder. A plurality of spaced apart mounting brackets are configured for affixing the ladder vertically to a stationary member, the stationary member not forming part of the invention. In this version, a drive unit retained within a carriage is mounted in proximity to the racks. The drive unit interacts with the racks to move the carriage upwardly and downwardly along the racks. A speed limiter is also disclosed that can be retained within the carriage below the drive unit and mounted in proximity to one of the racks. The speed limiter interacts with the rack to produce a breaking action if the drive unit fails, preventing the carriage to drop down quickly. Single rack and inclined rack versions are disclosed as alternatives.