Electric Machine Locking Mechanism for Shaft Torque Access
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Solution Overview
Problem
Existing electric machines face challenges in securely attaching and detaching loads from shafts, especially when the shaft extends beyond the motor, making it difficult to apply torque or lock the load due to inaccessible ends.
Innovation Solution
A locking mechanism with a pin and spring system that allows selective rotation or locking of the rotor relative to the housing, enabling easy assembly and disassembly by switching between two modes, and a seal to facilitate pin movement for secure locking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the shaft extends out of the motor on both ends, then it is easier to hold the shaft stationary while applying torque to the nut, but the device complexity increases
Solution Approach 1:
The locking mechanism is divided into separate components: a locking pin, a actuating mechanism, and engagement features on the shaft. This segmentation allows the locking function to be added without requiring the shaft itself to be more complex, resolving the contradiction by separating the holding function from the shaft structure.
Solution Approach 2:
A locking pin acts as an intermediary element between the housing and the shaft. This mediator provides the shaft holding stationary capability without modifying the shaft's basic structure, thus improving ease of operation while maintaining simple device complexity.
2Device complexity
If only the load end of the shaft protrudes from the motor, then the device complexity is reduced, but it becomes difficult to apply torque to the nut or remove the load
Solution Approach 1:
The locking pin serves as a mediator that provides mechanical advantage and leverage points for applying torque. By engaging the pin with features on the shaft, it creates accessible points for tool application even when the shaft end is not accessible, thus improving ease of operation without increasing device complexity.
Solution Approach 2:
The locking mechanism replaces the need for direct mechanical access to the shaft end. Instead of requiring hand tools to be applied directly to the shaft or nut, the locking pin system provides alternative mechanical leverage points that can be accessed from the motor housing exterior.
3Ease of operation
If a locking mechanism is added to selectively lock the rotor, then the ease of operation for assembly and disassembly is improved, but the device complexity increases
Solution Approach 1:
The locking and unlocking functions are extracted as separate, discrete actions through the locking pin mechanism. The pin can be independently actuated to lock or unlock the rotor without affecting other motor functions, providing easy assembly and disassembly while keeping the added complexity minimal and modular.
Solution Approach 2:
The locking mechanism is designed to be self-actuating through spring biasing and cam engagement. Once the rotor is in the desired position, the spring automatically engages the locking pin, providing self-service locking without requiring additional actuators or complex control systems, thus improving ease of operation with minimal increase in device complexity.
4Ease of operation
If the locking mechanism is made accessible through an opening in the housing, then the ease of operation is improved, but the reliability decreases due to potential contamination
Solution Approach 1:
A flexible seal member, such as a lip seal or elastomeric seal, is positioned around the locking pin where it passes through the housing opening. This flexible film maintains sealing integrity while allowing the pin to move in and out, thus providing both ease of operation through accessibility and reliability through contamination prevention.
Solution Approach 2:
The sealing approach moves from a planar seal to a three-dimensional seal geometry that accommodates the linear motion of the locking pin. By creating a seal chamber or recess that follows the pin's movement path, the seal maintains continuous contact with the pin surface throughout its travel, preserving sealing integrity while allowing access for operation.
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 solution reduces costs, improves serviceability, and enhances performance by allowing efficient and reliable locking of shafts, making it easier to secure and remove loads from electric machines, particularly in applications like pumps where access is limited.
Implementation Method 1
The motor also includes a spring to bias the locking mechanism in the first mode
Implementation Method 2
The seal is adapted to permit movement of the pin to selectively slide the pin
Data Source
AI summary
An electric machine is provided. The machine includes a housing and a coil operably connected to the housing. The machine also includes a rotor. The rotor is rotatably secured to the housing and defines a first end of the housing which extends outwardly from a first end of the housing. The machine also includes a locking mechanism connected to the housing and selectively connected to the rotor. The locking mechanism is adapted to selectively provide a first mode in which the rotor may rotate relative to the housing and a second mode in which the rotor may not rotate relative to the housing.