Oscillating Work Tool Housing Layout for Vibration Isolation

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Solution Overview

Problem

Existing work tools experience increased vibration due to the arrangement of heavy components such as motors and transmitting mechanisms close to the spindle, leading to reduced moment of inertia and instability during operation.

Innovation Solution

A vibration-isolating housing with a two-layered structure, where the spindle is arranged orthogonally to the motor output shaft, and heavy components are distributed to balance the moment of inertia, using elastic members to connect the outer and inner housings and isolate vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the spindle is arranged in parallel to the output shaft of the motor, then the work tool can be reduced in size, but the moment of inertia of the housing is reduced and vibration increases

Engineering Contradiction:
Improvesize of work toolVSAvoidvibration during operation
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent pre-arranges heavy members (motor, transmitting mechanism) at specific positions in the housing before operation to optimize the moment of inertia distribution. This preliminary arrangement ensures that the center of gravity and moment of inertia are properly distributed to reduce vibration during actual use, while still allowing the spindle to be positioned close to the motor for compact size.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the arrangement parameters of heavy members within the housing, specifically positioning them to optimize the moment of inertia. By adjusting the spatial distribution of these components, the patent achieves a balance between maintaining compact dimensions and reducing vibration through improved inertial characteristics.

Inventive Principle:
Principle #35Parameter changes

2Length of moving object

If heavy members such as motor and transmitting mechanism are arranged closer to the spindle, then the work tool can be reduced in size, but the moment of inertia is reduced causing increased vibration

Engineering Contradiction:
Improvedistance from motor to spindleVSAvoidstability during operation
Core Design Contradiction:
Length of moving objectVSStability of the object's composition

Solution Approach 1:

The patent pre-configures the housing with heavy members positioned to optimize moment of inertia distribution before the tool operates. This preliminary arrangement ensures stability during operation by properly distributing mass, while still allowing compact positioning of the motor and spindle.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent optimizes the spatial parameters of heavy member arrangement within the housing, adjusting their positions to achieve the desired moment of inertia. This parameter optimization enables the motor to be positioned closer to the spindle for compactness while maintaining operational stability through improved inertial distribution.

Inventive Principle:
Principle #35Parameter changes

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 solution effectively reduces vibrations and stabilizes the tool, enhancing operational stability and reducing the transmission of vibrations to the outer housing, allowing for more precise and comfortable use.

Implementation Method 1

the inner housing is connected to the body housing via a plurality of elastic members

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3587039B1Work tool
Publication Date: 2023.06.28 MAKITA CORP
  • EP3587039B1 patent drawingFigure 1
  • EP3587039B1 patent drawingFigure 2
  • EP3587039B1 patent drawingFigure 3

AI summary

A work tool (100, 101) comprising: a motor (53) having an output shaft (531), the output shaft being rotatable around a first axis (A2); a spindle (51) having a tool mounting part (511) and configured to reciprocally rotate around a second axis (Al) by power of the motor and thereby oscillate a tool accessory mounted to the tool mounting part within an oscillation plane (OP), the second axis being parallel to the first axis, the oscillation plane being orthogonal to the second axis; and an elongate housing (3) in which the motor and the spindle are housed, wherein: the housing includes: a front housing part (38) in which at least the spindle is housed; and a rear housing part (39) connected to a rear end portion of the front housing part (38) and extending rearward, the front housing part (38) includes a first contact part (387), the first contact part having at least one first contact surface (380), the at least one first contact surface extending in a direction crossing the oscillation plane, the rear housing part (39) includes a second contact part (394), the second contact part having at least one second contact surface (390), the at least one second contact surface extending in the direction crossing the oscillation plane, and the first and second contact parts (387 and 394) are connected together in a state in which the at least one first contact surface (380) and the at least one second contact surface (390) are held in contact with each other.