Electric Machine Intermediate Bearing High-Speed Vibration Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric machines are not suitable for high rotational speeds greater than 8000 revolutions per minute due to structural limitations and vibration issues.
Innovation Solution
The electric machine incorporates three bearings, with two arranged on either side of the rotors and a third intermediate bearing between them, allowing for high-speed operation while maintaining the same size, using magnetic, oil, water, or roller bearings to support the shaft and rotors, and featuring two stators driving two integral rotors within a single frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If two end bearings are used to support the shaft and rotors, then the machine structure is simple, but the machine cannot operate at high rotational speeds greater than 8000 rpm
Solution Approach 1:
The bearing support system is segmented into three distinct bearings: two end bearings positioned at the ends of the shaft and one intermediate bearing positioned between the two rotors. This segmentation allows each bearing to independently support specific sections of the shaft, reducing vibration and deflection at high speeds without requiring a completely redesigned bearing system
2Speed
If the machine size is increased to support high-speed operation, then high rotational speeds can be achieved, but the machine size becomes larger
Solution Approach 1:
The intermediate bearing is positioned in the axial dimension between the two rotors rather than increasing the radial dimension of the machine. This allows the machine to achieve high-speed capability by utilizing the existing axial space between rotors, avoiding an increase in overall machine size while still providing the necessary structural support for speeds greater than 8000 rpm
3Reliability
If conventional bearing arrangements are used, then the machine structure is simple, but vibrations and deflection increase at high speeds
Solution Approach 1:
The intermediate bearing acts as an intermediary support element positioned between the two rotors on the shaft. It provides additional support at a critical location where vibration and deflection are most pronounced at high speeds, effectively reducing these adverse effects without requiring complete redesign of the entire bearing system or increased machine size
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
Enables operation at speeds greater than 8000 rpm, reduces vibrations and deflection, and increases natural frequencies, thereby enhancing reliability and electrical power without increasing machine size.
Implementation Method 1
two end bearings supporting the shaft at each of these ends
Implementation Method 2
at least two bearings, capable of supporting the two rotors and the shaft
Implementation Method 3
each bearing is one of the group consisting of: a magnetic bearing, an oil bearing, a water bearing, a gas bearing and a roller bearing
Implementation Method 4
each bearing is one of the group consisting of: a magnetic bearing, an oil bearing, a water bearing, a gas bearing and a roller bearing
Implementation Method 5
each bearing is one of the group consisting of: a magnetic bearing, an oil bearing, a water bearing, a gas bearing and a roller bearing
Implementation Method 6
each bearing is one of the group consisting of: a magnetic bearing, an oil bearing, a water bearing, a gas bearing and a roller bearing
Data Source
Figure 1
Figure 2
AI summary
The machine (10) has a shaft (22) movable in rotation around an axis of rotation (X). End bearings (24, 26) and an intermediate bearing (28) support two rotors (16, 20) and the shaft, where each rotor is interdependent of the shaft. The intermediate bearing is located between the rotors along the axis of rotation. Each bearing is a magnetic bearing, an oil bearing, a water bearing, a gas bearing or a roller bearing. The rotors are positioned inside a single frame (12). Stators (14, 18) drive the rotors in rotation.