Electric Motor Mounting Apertures Vibration Stability
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Solution Overview
Problem
Existing electric motor designs for electronic throttle control units face issues with vibration causing the laser welded connection between the mounting plate and the rim of the housing to work loose during testing.
Innovation Solution
The electric motor features mounting apertures on both the housing and the end cap, with the motor mounting bolts securing the end cap and housing together, utilizing a plastics inner part and a metal outer part with arcuate depressions for enhanced stability, and crimping for secure fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a laser welded connection is used between the mounting plate and the rim of the housing, then the motor can be assembled efficiently, but the connection works loose during vibration testing
Solution Approach 1:
The mounting structure is divided into multiple components: the housing with flanges, the end cap with portions extending over the flanges, and separate mounting bolts. This segmentation allows each component to perform its specific function - the laser welded connection provides initial positioning while the bolts provide vibration-resistant fastening.
Solution Approach 2:
The mounting bolts act as an intermediary element between the housing and the customer's unit body. Instead of relying solely on the laser welded mounting plate, the bolts provide an additional mechanical fastening mechanism that prevents loosening during vibration while maintaining assembly efficiency.
2Device complexity
If the end cap is simply fitted into the housing, then assembly is simple, but the connection is not stable under vibration
Solution Approach 1:
The end cap design merges multiple functions into a single component: it closes the housing opening, supports the brush gear and terminals, and provides portions that extend over the flanges to create mounting apertures. This integration maintains simplicity while enabling stable vibration-resistant mounting.
Solution Approach 2:
The end cap is designed with pre-formed portions extending over the flanges, which are then secured through the mounting apertures with bolts. This preliminary structuring of the end cap enables the vibration-resistant connection without adding complex assembly steps.
3Reliability
If mounting apertures are added to both housing and end cap, then vibration resistance is improved, but manufacturing complexity increases
Solution Approach 1:
The flanges on the housing and portions on the end cap serve multiple functions: they provide structural support, define mounting apertures for vibration-resistant fastening, and maintain the mechanical integrity of the motor assembly. This multi-functionality reduces the need for separate components.
Solution Approach 2:
The motor assembly uses composite construction with a metal housing and a plastics end cap. This allows the end cap to be molded with integrated mounting features, reducing manufacturing complexity compared to machining apertures in metal parts.
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 configuration significantly enhances the motor's stability and prevents loose connections during vibration testing, ensuring reliable operation in electronic throttle control units.
Implementation Method 1
the metal outer part supports a bearing and has at least two arcuate depressions which are press fitted in the open end of the metal housing
Implementation Method 2
the metal housing and the metal outer part of the end cap are crimped together
Implementation Method 3
the plastics inner part of the end cap is fixed to the metal outer part of the end cap by two plastics posts integral with the plastics inner part and passing through apertures in the metal outer part
Implementation Method 4
the motor mounting bolts hold the end cap and housing together
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The electric motor is a fitment to a customer's unit and in particular to a customer's electronic throttle control unit. The motor comprises a can-like metal housing 10 having one or more outwardly extending flanges 21, 22 and an end cap 15 closing the open end 12 of the housing 10. The end cap 15 comprises a plastics inner part 16 which fits within the open end of the housing 10 and which supports motor terminals 17 and brush gear 18 for the motor. The end cap 15 also comprises a metal outer part 20 which has one or more portions 29, 30 extending over the flange or flanges 21, 22 of the housing. The flange(s) of the metal housing and the aforesaid portion(s) of the metal outer part of the end cap 15 have apertures 24, 32 for receiving fastening members whereby the motor can be connected to the customer's unit. A method of fitting an electric motor to a customer's unit is also disclosed.