Motor Drive Assembly With PCB-Aligned Stator Contacts
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Solution Overview
Problem
The laminated stator core in existing drive assemblies has significant tolerance variations, making it difficult to achieve precise electrical contact with the stator windings, especially when using press-in contacts, due to the mismatch between the smaller permitted positional tolerance of the press-in pins and the larger height tolerance of the stator core.
Innovation Solution
The drive assembly integrates a stator housing with integral bearing and supporting surfaces for the stator insulation parts, using a latching connection to secure the upper and lower parts, and incorporates centring pins for precise positioning of the printed circuit board, ensuring consistent alignment of terminal contacts with the circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If press-in contacts are used to contact stator windings, then electrical connection is achieved, but the positional tolerance of press-in pins must be significantly smaller than the height tolerance of the laminated stator core, making assembly difficult
Solution Approach 1:
A contact carrier is introduced as an intermediary component between the terminal contacts and the printed circuit board. The contact carrier is integrated with the lower part of the stator insulation and provides a stable mounting base for the terminal contacts, decoupling their position from the variable height of the laminated stator core. This mediator absorbs the tolerance mismatch and enables reliable electrical connection without requiring extremely precise press-in positioning.
Solution Approach 2:
The contact carrier is merged with the lower part of the stator insulation as an integral component. This combination creates a unified structure where the terminal contacts are automatically positioned relative to the printed circuit board through their integration with the stator insulation parts, eliminating the need for separate positioning mechanisms and reducing assembly complexity.
2Ease of manufacture
If the laminated stator core has large tolerance, then manufacturing is easier, but the overall height of the subassembly varies considerably, making precise electrical contact difficult
Solution Approach 1:
The contact carrier serves as a mediator that decouples the electrical contact positioning from the laminated stator core height. By integrating the contact carrier with the lower part of the stator insulation and providing bearing surfaces on the stator housing, the system allows the stator core to have large manufacturing tolerances while maintaining precise electrical contact through the stable positioning provided by the contact carrier and bearing surfaces.
Solution Approach 2:
The invention changes the positioning reference from the laminated stator core height to the bearing surfaces formed on the stator housing. This parameter change allows the electrical contact position to be defined by the bearing surfaces and contact carrier geometry rather than by the variable height of the stator core, thereby maintaining precision despite large core tolerances.
3Reliability
If terminal contacts are pressed into printed circuit board openings, then electrical contact is made, but the permitted positional tolerance of press-in pins is significantly smaller than the height tolerance of the stator core
Solution Approach 1:
The contact carrier acts as an intermediary that provides a stable reference for terminal contact positioning. By integrating the contact carrier with the lower part of the stator insulation and positioning it using bearing surfaces on the stator housing, the system ensures that terminal contacts are reliably positioned relative to the printed circuit board without requiring the press-in pins to have extremely tight tolerances. The intermediary absorbs the tolerance variations.
4Ease of manufacture
If the stator insulation consists of separate upper and lower parts, then assembly on the laminated stator core is easier, but the overall height tolerance increases
Solution Approach 1:
The stator insulation is segmented into upper and lower parts that are assembled around the laminated stator core. The lower part is integrated with the contact carrier and provides bearing surfaces for positioning. This segmentation allows easier assembly on the stator core while the bearing surfaces and contact carrier compensate for the resulting height tolerances, maintaining precise electrical contact positioning.
Data Source
Figure 1
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Figure 4~10
AI summary
The invention relates to a drive assembly having an electric motor (2), having a stator housing (14), a stator (12) accommodated therein and having at least one winding (24), a stator insulation (22) which has a lower part (22U) and an upper part (22O), wherein the lower part (22U) rests against at least one bearing surface (40) in the stator housing (14), terminal contacts (28) for the winding (24), wherein the terminal contacts (28) are held in a contact carrier (36), which is provided on the lower part (22U) of the stator insulation (22), and a printed circuit board (16), which rests on at least one supporting surface (42) in the stator housing (14), wherein the terminal contacts (28) are in contact with associated conductor tracks of the printed circuit board (16).