Rotor Spring Retaining Permanent Magnets Against Tolerances
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Solution Overview
Problem
In electric machines, such as scroll compressors for motor vehicle air conditioners, large manufacturing tolerances can lead to poor placement of permanent magnets within the rotor, resulting in inadequate retention and potential mechanical issues during rotation.
Innovation Solution
The use of springs positioned between the rotor's core and magnet faces, exerting a radial force through deformation to securely hold the magnet in place, with a design featuring a central rounded portion and inverted curvature end portions, and a beveled end with a slot to reduce rigidity, ensuring effective retention across varying speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If large manufacturing tolerances are used to reduce manufacturing costs, then manufacturing cost decreases, but magnet placement precision deteriorates
Solution Approach 1:
The patent changes the physical state and geometric parameters of the spring element to create an adaptive retention system. The spring transitions between compressed and relaxed states to dynamically adjust magnet retention, compensating for dimensional variations caused by large manufacturing tolerances in the rotor housing and magnet components.
2Device complexity
If simple magnet retention structures are used to reduce device complexity, then device complexity decreases, but magnet retention reliability deteriorates
Solution Approach 1:
The spring element functions as a self-adjusting retention mechanism that automatically compensates for dimensional variations and operational forces. The elastic deformation of the spring provides continuous adaptive retention pressure on the magnet, ensuring reliable fixation without requiring complex external control systems or multiple retention components.
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 solution ensures reliable magnet retention within the rotor housings, maintaining stability and mechanical integrity regardless of rotor speed, even with wide manufacturing tolerances, by applying a radial force through spring deformation, thus enhancing the operational reliability of electric machines.
Implementation Method 1
springs for the radial retention of the associated permanent magnet... These springs hold the magnet within its housing against the edges of the rotor arms by exerting a radial force on the magnet from the inside to the outside of the rotor
Data Source
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AI summary
The invention essentially relates to a rotor (100) for an electric machine comprising a central core (101) and arms (102) extending radially relative to the core (101). Permanent magnets (114) are positioned inside recesses (111) each defined by two surfaces of two adjacent arms (102), an outer surface of the core (101), and the edges (105) of the arms (102). According to the invention, springs (122) are positioned inside the recesses (111) between the outer core (101) surface and a surface of the magnet (114) facing the axis (X) of the rotor (100). Said springs (122) ensure that the permanent magnet (114) is supported inside the recess (111) thereof against the flanges (105) of the arms of the rotor, by exerting a radial force (F1) by deformation on the permanent magnet (114) from the inside toward the outside of the rotor (100). The invention also relates to the springs (122) as such, which comprise a central rounded portion and two rounded end portions located on either side of the central rounded portion, having inverted curves. The invention further relates to a spring for supporting related permanent magnets.