Brush Cutter Drive Shaft Bearing Assembly for Lower Rotational Resistance
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Solution Overview
Problem
Conventional brush cutters using bushes (slide bearings) for the drive shaft experience high rotational resistance, leading to shortened battery life in rechargeable models.
Innovation Solution
A brush cutter with a drive shaft bearing system comprising a ball bearing, a cylindrical holder divided into two members, and an elastic ring, where the bearing is seated in an inner groove and the elastic ring in an outer groove, reducing rotational resistance and facilitating assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a bush (slide bearing) is used to support the drive shaft, then the structure is simple and easy to manufacture, but the rotational resistance increases and battery life shortens
Solution Approach 1:
The patent replaces the bush (slide bearing) with a ball bearing to reduce rotational resistance. The ball bearing uses rolling contact instead of sliding contact, significantly lowering friction and energy loss, thereby extending battery life in rechargeable brush cutters while maintaining manufacturing feasibility.
Solution Approach 2:
The patent changes the bearing type from sliding contact to rolling contact, fundamentally altering the friction parameter. This parameter change reduces rotational resistance and energy consumption, directly addressing the battery life issue without compromising ease of manufacture.
2Duration of action of moving object
If a ball bearing is used to reduce rotational resistance, then battery life is extended, but the device complexity increases
Solution Approach 1:
The holder is divided into two separate members: an outer holder and an inner holder. This segmentation allows the ball bearing to be installed in the inner holder, which is then inserted into the outer holder. The segmentation simplifies the assembly process and reduces device complexity by making the bearing installation modular and manageable.
Solution Approach 2:
The inner holder containing the ball bearing is nested within the outer holder. This nested structure consolidates multiple components into a compact assembly, reducing overall device complexity while maintaining the benefits of the ball bearing for extended battery life.
3Device complexity
If the holder is made as a single piece, then the structure is simple, but assembly accuracy and positioning are difficult to achieve
Solution Approach 1:
The holder is segmented into outer holder and inner holder components. The inner holder is specifically designed to hold the ball bearing with precise positioning features. This segmentation enables high assembly accuracy for the bearing installation while keeping the overall structure manageable through modular design.
Solution Approach 2:
The inner holder is pre-assembled with the ball bearing before being installed in the outer holder. This preliminary action ensures precise positioning of the bearing within the inner holder, and the subsequent installation into the outer holder maintains this precision, achieving high assembly accuracy through staged assembly.
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 significantly reduces rotational resistance, extends battery life in rechargeable brush cutters, and offers improved assembly accuracy and reduced weight, while allowing adjustable press-fitting loads.
Implementation Method 1
an elastic ring, wherein the holder is formed by combining two members divided parallel to an axial direction, and is assembled in a state where an outer peripheral part of the bearing is stored in an inner groove formed on an inner peripheral surface of the holder in a peripheral direction, and the elastic ring is stored in an outer groove formed on an outer peripheral surface of the holder in the peripheral direction
Data Source
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AI summary
[Object] To provide a shaft bearing capable of reducing rotational resistance of a drive shaft by use of a ball bearing instead of a bush (slide bearing). [Constitution] A shaft bearing includes a bearing, a cylindrical holder, and an elastic ring. The holder is formed by combining two members divided parallel to an axial direction, and is assembled in a state where an outer peripheral part of the bearing is stored in an inner groove formed on an inner peripheral surface of the holder in a peripheral direction, and the elastic ring is stored in an outer groove formed on an outer peripheral surface of the holder in the peripheral direction.