Motor assembly
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Solution Overview
Problem
Vacuum cleaner motors experience premature bearing wear due to eccentricity caused by radial misalignment during assembly, leading to reduced bearing life and increased vibration, especially when rotational speed is increased to maintain suction force with a smaller motor size.
Innovation Solution
The motor design includes a housing cover with a guide rib that contacts the inner surface of the motor housing, preventing radial misalignment and ensuring proper bearing alignment, thereby minimizing wear and extending bearing life even at high speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the motor size is reduced to meet consumer demand for smaller vacuum cleaners, then the suction force may decrease, but increasing the rotational speed to maintain suction force causes increased bearing wear and shortened bearing life due to eccentricity
Solution Approach 1:
The guide rib is pre-formed on the housing cover to establish correct radial alignment before the bearing assembly is installed. This preliminary alignment action prevents eccentricity from occurring during assembly, ensuring that even when the motor operates at high speeds in a reduced-size configuration, the bearing maintains proper alignment and achieves extended service life
2Ease of manufacture
If fastening tolerance is used to facilitate assembly of the bearing housing, then assembly ease is improved, but radial misalignment occurs causing the rotation shaft to become eccentric from the center axis
Solution Approach 1:
The guide rib acts as an intermediary element between the housing cover and the bearing assembly. It mediates the assembly process by providing a physical guide that ensures the bearing housing is correctly positioned radially during assembly, thereby eliminating misalignment issues while preserving the benefits of tolerance-based assembly
3Productivity
If the rotational speed of the motor is increased to maintain suction force with a smaller motor size, then the suction force is maintained, but the vibration of the motor rotation shaft becomes large and bearing wear worsens
Solution Approach 1:
The guide rib establishes proper radial alignment of the rotation shaft before high-speed operation begins. This preliminary alignment ensures that when the motor operates at increased rotational speeds to maintain suction force, the bearing experiences minimal eccentricity and vibration, thereby preventing accelerated wear and maintaining reliability
Data Source
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AI summary
A motor according to an embodiment of the present invention includes a housing that has a bottom portion on which a first bearing accommodating portion is formed and a cylindrical side surface portion which extends from an edge of the bottom portion; a rotor assembly that has a rotation shaft and a rotor which is mounted on an outer circumferential surface of the rotation shaft and is accommodated in an inside portion of the housing; a stator assembly that is accommodated in an inside portion of the housing and surrounds the rotor; a housing cover that is coupled to an upper end of the housing and on which a second bearing accommodating portion is formed at a central portion thereof; a flow guide that is seated on the upper side of the housing cover; an impeller that is connected to the rotation shaft at an upper side of the flow guide; an impeller cover that covers the impeller; a first bearing that is accommodated in the first bearing accommodating portion and into which one end portion of the rotation shaft is inserted; and a second bearing that is accommodated in the second bearing accommodating portion and into which the other end of the rotation shaft is inserted, in which the housing cover includes a cover body on which an opening portion is formed therein, a plurality of connection arms that connects the second bearing accommodating portion and an edge of the opening portion to each other, and a guide rib that extends from the edge of the opening portion.