Steering Gear Lubrication Layout for Lower Weight and Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional steering devices in electric power steering systems are hindered by increased weight due to the amount of oil required for lubrication, which also causes friction and operational inefficiencies.
Innovation Solution
The steering device is designed with a first gear mechanism lubricated by grease and separated from an oil chamber, and a belt-type transmission mechanism that reduces the need for oil, thereby minimizing weight and friction while improving operability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mechanical parts are lubricated with oil stored in the case (oil chamber), then the speed reducer can be properly lubricated, but the amount of oil stored in the oil chamber is increased, which hinders weight reduction
Solution Approach 1:
The patent divides the lubrication system into two separate segments: an oil chamber for the speed reducer and a grease chamber for the rack and pinion mechanism. This segmentation allows each mechanism to be lubricated with the most appropriate lubricant in the most space-efficient way, eliminating the need to store large amounts of oil that would be required if oil were used to lubricate the rack and pinion.
Solution Approach 2:
The patent applies different lubrication qualities to different parts of the system: oil is used specifically in the speed reducer where it is most effective, while grease is used in the rack and pinion mechanism where it provides sufficient lubrication with minimal space requirements. This local differentiation of lubrication quality optimizes both performance and weight.
2Reliability
If oil is used to lubricate the speed reducer, then the lubrication effectiveness is improved, but the friction caused by oil agitation increases, which deteriorates operability
Solution Approach 1:
The patent segments the lubrication system so that oil is confined to the speed reducer where it provides effective lubrication without causing operability issues, while the rack and pinion mechanism uses grease that does not create agitation friction. This segmentation ensures that the harmful effects of oil agitation are localized and do not affect overall system operability.
Solution Approach 2:
The patent extracts the oil lubrication function from the overall steering mechanism and applies it only to the speed reducer, while using grease for the rack and pinion. This extraction eliminates the problem of oil agitation affecting operability in the steering mechanism while preserving the benefits of oil lubrication in the speed reducer.
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 configuration achieves weight reduction and improved operational accuracy by minimizing oil usage and reducing friction, while maintaining reliable lubrication and operational efficiency.
Implementation Method 1
a seal member that seals between the case and the cover
Implementation Method 2
The first gear mechanism includes: conversion mechanism parts configured to convert the direction of the rotation; and a case that houses the conversion mechanism parts. The interior of the case is formed as a separation space separated from the oil chamber by the seal member.
Implementation Method 3
the gear case forms an oil chamber that houses the reduction mechanism parts
Data Source
AI summary
A steering device according to one aspect of the invention includes: a first gear mechanism configured to receive rotation of steering wheel operation, convert a direction of the rotation, and output converted rotation as primary rotation; and a second gear mechanism configured to receive the primary rotation output from the first gear mechanism, decelerate the primary rotation, and output decelerated rotation. The first gear mechanism includes: conversion mechanism parts configured to convert the direction of the rotation; and a case that houses the conversion mechanism parts. The second gear mechanism includes: reduction mechanism parts configured to decelerate the primary rotation; and a gear case that houses the reduction mechanism parts. The gear case forms an oil chamber that houses the reduction mechanism parts. The case forms a separation space separated from the oil chamber by a seal member.