Motor Rotor Positioning Marker and Pinion Alignment
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Solution Overview
Problem
Conventional motors with rotors experience positional deviations due to manufacturing and assembly errors, affecting the alignment of magnetic poles and pinion teeth, which is critical in applications like refrigerant valves where precise rotation is needed.
Innovation Solution
Incorporating a positioning marker on the magnet and using a concave-convex fitting structure between the rotor main body and integral rotation unit to ensure a set relative arrangement, reducing positional deviations by fixing the rotor to the magnet with insert molding and aligning the pinion teeth accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing and assembly processes are used without positioning markers, then the manufacturing process is simple, but the relative position between magnetic poles and pinion teeth varies among rotors
Solution Approach 1:
A positioning marker is provided on the magnet before assembly to establish a reference position. This preliminary positioning feature enables accurate alignment of the rotor main body and integral rotation unit during assembly, thereby suppressing variation in the relative position between magnetic poles and pinion teeth among rotors.
Solution Approach 2:
The positioning marker acts as an intermediary reference element between the magnet and the rotor components. It mediates the alignment process by providing a fixed reference point that facilitates precise positioning of the rotor main body relative to the magnet and the integral rotation unit relative to the rotor main body.
2Strength
If insert molding is used to fix the rotor main body to the magnet, then the fixation is strong, but positioning errors from manufacturing and assembly accumulate
Solution Approach 1:
The positioning marker is established on the magnet before the insert molding process. This preliminary reference enables precise positioning of the rotor main body during injection molding, allowing the strong fixation provided by insert molding to be combined with accurate position control, thereby preventing accumulation of positioning errors.
3Ease of manufacture
If the integral rotation unit can be assembled in any relative arrangement to the rotor main body, then the assembly is easy, but the position of pinion teeth relative to magnetic poles varies
Solution Approach 1:
A fitting structure with asymmetric concave and convex portions is provided between the rotor main body and the integral rotation unit. This asymmetric design enables the components to be assembled in only one specific relative arrangement, ensuring that the pinion teeth are positioned at the correct angle relative to the magnetic poles while still maintaining ease of assembly through the self-aligning nature of the fitting structure.
Data Source
AI summary
To suppress variation, among rotors, in a relative position between the position of magnetic poles of a magnet and the rotation position (for example, the position of teeth of a pinion) of an integral rotation unit configured to rotate integrally with the rotor main body. A motor includes: a rotor including a magnet fixed to an outer periphery of a rotor main body, and an integral rotation unit assembled to the rotor main body; and a spindle configured to rotatably support the rotor. The magnet includes a positioning marker used when the rotor main body is fixed to the magnet, and the integral rotation unit and the rotor main body are configured to be capable of being assembled in a set relative arrangement.