Impact Resistant Electric Motor Axial Spacing Design
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Solution Overview
Problem
Direct current (DC) electric motors are prone to damage when subjected to impact forces, such as dropping, due to component shifting within the motor.
Innovation Solution
The electric motor design incorporates a front force dissipation component, such as a flywheel, and strategically positioned bearings with varying axial spacings to absorb and dissipate impact forces, along with biasing mechanisms like compression springs or wave washers to return components to their operational positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the motor components are tightly fitted to maximize space utilization, then the motor size is minimized, but the motor becomes vulnerable to impact damage due to component shifting
Solution Approach 1:
The patent applies beforehand cushioning by providing axially spaced relationships between bearings and motor covers, creating clearance spaces that absorb impact forces before they can damage internal components. The front bearing is positioned with a first axial spacing from the front cover, and the rear bearing with a second axial spacing from the rear cover, establishing protective buffers in advance of any impact event.
Solution Approach 2:
The patent utilizes parameter changes by varying the axial spacing parameters of the bearing arrangements. The first axial spacing (front bearing to front cover) and second axial spacing (rear bearing to rear cover) are specifically configured to optimize impact absorption while maintaining compact overall dimensions. This parameter optimization allows the motor to achieve both small size and high impact resistance.
2Reliability
If axial spacing between bearings and covers is increased to absorb impact forces, then impact resistance is improved, but the motor length increases
Solution Approach 1:
The patent optimizes the axial spacing parameters to achieve the best balance between impact resistance and compact size. By carefully selecting the first axial spacing (front bearing to front cover) and second axial spacing (rear bearing to rear cover), the design minimizes motor length while maintaining sufficient clearance for impact absorption. This parameter optimization is critical to resolving the contradiction between compactness and impact resistance.
Solution Approach 2:
The patent may employ asymmetric bearing arrangements where the first axial spacing differs from the second axial spacing. This asymmetric configuration allows optimal impact absorption in the direction of expected impact forces while minimizing the overall motor length in other directions, thereby resolving the contradiction between impact resistance and compact dimensions.
3Reliability
If components are allowed to move axially to dissipate impact forces, then damage from impact is reduced, but component stability during operation decreases
Solution Approach 1:
The patent applies dynamics by creating a system that is stable during normal operation but can dynamically adjust during impact events. The axially spaced bearing arrangements allow controlled movement of components relative to each other when impact forces are applied, enabling the motor to absorb impact energy through elastic deformation and component shifting, while maintaining operational stability during normal use.
Solution Approach 2:
The pre-configured axial clearances act as beforehand cushioning that becomes active only during impact events. During normal operation, the components remain in their designed positions with stable spacing. When impact occurs, the pre-established clearances allow controlled movement and force dissipation, protecting internal components from damage while maintaining operational integrity.
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 design minimizes damage from impact forces by allowing bearings to move axially and dissipating forces effectively, reducing the likelihood of component collision with the motor covers and maintaining motor functionality.
Implementation Method 1
A flywheel assembly can be coupled to the armature shaft to maintain rotational speed of the motor by virtue of the inertia of the flywheel
Implementation Method 2
The front force dissipation component can absorb an impact force applied to the motor when, e.g., the front force dissipation component and the front cover contact each other due to a shifting occasioned by the impact force
Implementation Method 3
biasing mechanisms like compression springs or wave washers to return components to their operational positions
Data Source
AI summary
Electric motors and machines including such electric motors, the electric motors having improved impact resistance. Features of the electric motors minimize axial shifting of the motor shaft and other components of the electric motor, and/or minimize damage to components caused by such axial shifting occasioned by an impact force on the motor.