Handheld Blower Inlet Assembly Design for Noise Reduction

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Solution Overview

Problem

Outdoor power equipment, such as handheld blowers, generate significant noise, which can be a concern for operators and bystanders, and existing solutions often increase the size, cost, and complexity of the equipment while not adequately addressing noise reduction.

Innovation Solution

The design incorporates an inlet mesh inset within the housing and an angled inlet aperture that directs noise downward, combined with an integrated muffler system, to reduce noise emissions without adding extra components, thereby improving the quietness of the blower.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If traditional blower designs are used, then power and productivity are maintained, but noise levels are high and disturb operators and bystanders

Engineering Contradiction:

Improvenoise levelsVSAvoidblower performance

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The inlet aperture is angled relative to the blower tube axis, directing noise downward in a different spatial dimension away from the operator. This angular orientation redirects the noise path without affecting the forward airflow direction, separating the noise emission dimension from the productivity dimension.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The inlet mesh, originally designed for safety to prevent objects from entering the blower, is repurposed as a noise reduction component. The mesh structure absorbs and diffuses noise waves while maintaining its protective function, converting a safety feature into a dual-purpose noise control solution.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If additional noise reduction components are added, then noise levels decrease, but device complexity and cost increase

Engineering Contradiction:

Improvenoise emissionsVSAvoidcomponent count

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The inlet mesh serves multiple functions: it acts as a safety guard to prevent objects from entering the blower, serves as a structural component of the inlet assembly, and functions as a noise reduction element. This multi-functionality eliminates the need for separate noise control components, reducing overall device complexity while achieving noise reduction goals.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The noise reduction function is merged into the existing inlet assembly structure rather than being implemented as a separate component. The angled inlet aperture and inlet mesh are integrated into the housing design, combining noise control with the air intake system to avoid increasing component count.

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If the inlet aperture is angled to direct noise downward, then noise is directed away from the operator, but air intake efficiency may be affected

Engineering Contradiction:

Improvenoise directionVSAvoidair intake efficiency

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The inlet assembly is segmented into distinct functional zones: the angled inlet aperture for noise direction control, the inlet mesh for safety and noise reduction, and the internal passages optimized for airflow. This segmentation allows each component to specialize in its function without compromising overall performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inlet aperture angle is optimized to achieve the right balance between noise direction and airflow efficiency. By carefully selecting the angular parameter, the design directs noise downward away from the operator while maintaining sufficient air intake velocity and volume for effective blower operation.

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

This approach effectively reduces noise levels by directing noise away from the operator and into sound-absorptive terrain, while maintaining the reliability and performance of the blower, without increasing complexity or cost.

Implementation Method 1

an acoustic chamber into which the noise generated by the fan assembly may be captured or otherwise retained to reduce the amount of noise that escapes from the blower

Methodology Applied

Scientific EffectSound absorption: Acoustic Absorption

Implementation Method 2

an angled inlet aperture that directs noise downward

Methodology Applied

Scientific EffectSound direction: Acoustics

Data Source

PatentUS10670048B2Blower with improved sound reduction

Publication Date: 2020.06.02 HUSQVARNA AB

AI summary

A blower (100) may include a housing (110), a motor (120), a fan assembly (170) and an inlet assembly (160). The housing (110) may include a handle (140) operably coupled thereto. The fan assembly (170) may be operably coupled to the motor (120) to force air through a blower tube (150) responsive to operation of the motor (120). The blower tube (150) may define a tube axis (152). The inlet assembly (160) may provide a path for air to the fan assembly (170). The inlet assembly (160) may include an inlet aperture (162) formed at an end of the housing (110). The inlet assembly (160) may further include an inlet mesh (164) disposed within the housing (110) spaced apart from the inlet aperture (162).