Electric Motor with Adjustable Air Gap and Mechanical Braking
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Solution Overview
Problem
Conventional electric motors lack a mechanical braking mechanism, relying solely on electromagnetic field adjustments for speed control and braking, which is insufficient for holding or parking functions, and are inefficient in high-power applications compared to three-phase and permanently excited drives.
Innovation Solution
Integration of a mechanical braking device using conically designed stator and rotor with adjustable braking surfaces, actuated by the same mechanism for variable electromagnetic field control, allowing for enhanced braking and power transmission by shifting the rotor and stator relative to each other, enabling a mechanical braking effect without additional control devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If electromagnetic field adjustment is used for speed control and braking, then speed control is achieved, but braking efficiency is insufficient for holding or parking functions
Solution Approach 1:
The patent combines electromagnetic braking and mechanical braking into a single integrated system. The mechanical braking surfaces are integrated onto the rotor and stator components that already exist for electromagnetic operation, merging two braking mechanisms into one unified structure that provides both speed control and reliable holding functions.
Solution Approach 2:
The rotor and stator serve multiple functions: they generate electromagnetic force for motor operation, adjust the air gap for speed control, and provide braking surfaces for mechanical braking. This multi-functionality eliminates the need for separate braking components while achieving reliable holding and parking capabilities.
2Speed
If conical rotor and stator with adjustable air gap are used, then field weakening is achieved, but mechanical braking capability is lacking
Solution Approach 1:
The patent merges the air gap adjustment mechanism with mechanical braking surfaces on the same rotor and stator components. The conical geometry enables both air gap variation for speed control and provides inclined surfaces that function as braking surfaces when pressed together.
Solution Approach 2:
The system dynamically transitions between motor operation mode (with air gap adjustment for field weakening) and braking mode (with mechanical contact between braking surfaces). The same components adapt their function based on operational requirements, providing both speed control and mechanical braking capability.
3Device complexity
If the same actuator is used for air gap adjustment and braking actuation, then device complexity is reduced, but control precision may be compromised
Solution Approach 1:
A single actuator is designed to perform multiple functions: adjusting the air gap during motor operation and actuating the mechanical braking surfaces when braking is required. This universal actuator reduces the total number of control devices while maintaining sufficient control precision through proper design of the actuation mechanism.
Solution Approach 2:
The actuator dynamically switches between two operational modes: fine adjustment mode for air gap control during motor operation, and force application mode for engaging braking surfaces. The control system adapts the actuator's operation mode based on the current operational state, maintaining precision in both functions.
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
Significantly increases braking efficiency, allows for high-power applications with greater field weakening, and replaces conventional motors with a variably adjustable air gap, providing a self-locking function and efficient operation in production and emergency stops.
Implementation Method 1
electrically operating the electric motor to rotate the reel
Implementation Method 2
the relative position of the rotor and the stator to each other, and thus the size of the air gap and consequently the strength of the electromagnetic field, can be variably adjusted
Implementation Method 3
at least one stator-side braking surface (114) and at least one rotor-side braking surface (124), wherein a stator-side and a rotor-side braking surface are positionable against each other to produce a mechanical braking effect
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to an electric motor and a method for operating it. The electric motor 100 has a stator 110 and a rotor 120 with an air gap 112 located between them. The size of the air gap 112 can be variably adjusted by changing the relative position of the stator and rotor to each other within a motor-controlling adjustment range X1 using an actuator 130. To improve the braking effect of the electric motor and to ensure that the stator and rotor are fixed relative to each other when stationary, the invention provides a mechanical braking device 140. This device is formed by at least one stator-side braking surface 114 associated with the stator and at least one rotor-side braking surface 124 associated with the rotor.The actuator is further designed to apply a braking force to the stator-side and rotor-side braking surfaces against each other, while simultaneously changing the relative position of the rotor and stator to each other within a braking adjustment range.