Straddled Vehicle Rear Suspension Mass Centralization

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional straddled vehicles face challenges in mass centralization and space constraints due to the large and heavy rear suspension unit, which includes a reservoir and actuator, positioned at the rear of the engine, hindering kinetic performance and installation of other vehicle parts.

Innovation Solution

The rear suspension unit is reconfigured with the reservoir and actuator positioned ahead of the conventional location, overlapping with the transmission, allowing for mass centralization and increased space at the engine rear, while maintaining compact dimensions and adjustable damping force through an L-shaped layout and strategic placement of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rear suspension unit including reservoir and actuator is disposed at the rear of the engine, then the damping force adjustment function is achieved, but mass centralization is difficult to obtain

Engineering Contradiction:

Improvedamping force adjustment functionVSAvoidmass centralization

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The reservoir is relocated from the horizontal rear position to a vertical position above the transmission, utilizing the vertical dimension to resolve the spatial conflict. This allows the heavy rear suspension unit to be positioned more centrally in the vehicle's mass distribution while maintaining its functional integrity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the rear suspension unit including reservoir and actuator is disposed at the rear of the engine, then the damping force adjustment function is achieved, but space for installing other vehicle parts is reduced

Engineering Contradiction:

Improvedamping force adjustment functionVSAvoidspace at rear of engine

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

By moving the reservoir to the vertical space above the transmission, the patent frees up the horizontal rear engine area for other components while maintaining the rear suspension unit's damping adjustment capability.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The reservoir is positioned to overlap with the transmission in plan view, effectively nesting the reservoir space within the vertical envelope of the transmission area, thereby optimizing space utilization.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Weight of moving object

If the reservoir is positioned above the transmission, then mass centralization is achieved and space at engine rear is obtained, but interference with crankcase may occur

Engineering Contradiction:

Improvemass centralizationVSAvoidinterference with crankcase

Core Design Contradiction:

Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent specifies precise positioning boundaries: the reservoir is located at the rear of the cylinder head, above the transmission, and at the front of the crankcase rear end. This localized positioning ensures the reservoir occupies only the safe vertical space without encroaching on the crankcase area.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3960607B1Straddled vehicle

Publication Date: 2023.08.30 YAMAHA MOTOR CO LTD

Figure 1
Figure 2
Figure 3

AI summary

A reservoir (66) and an actuator (68) of a rear suspension unit (60) are disposed at the outside of a damper (63) and integrally provided to the damper (63). The reservoir (66) is disposed at the rear of an upper end (23t) of a cylinder head (23) of an engine (20), above a transmission (40), and at the front of a rear end (21b) of a crankcase (21).