Motor Bearing Pump Control for Speed- and Load-Dependent Gas Lubrication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The application of a gas-lubricated bearing in high-speed motor operation increases fluid friction and resistance, worsening electric efficiency, while in low-speed operation, the wedge and restriction effects are insufficient to form a reliable gas layer, leading to potential contact between the bearing and rotary shaft.
Innovation Solution
A motor bearing system with a rolling bearing and a gas-lubricated slide bearing, controlled by a pump and detector, switches between operation modes based on rotation speed and radial load to optimize gas layer formation and minimize electricity consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a gas-lubricated bearing is applied in high-speed motor operation, then friction is reduced, but fluid friction and resistance of the lubricating gas increase, worsening electric efficiency
Solution Approach 1:
The patent changes the operating parameters of the gas-lubricated bearing by adjusting gas pressure based on rotation speed. At high speeds where wedge and restriction effects are sufficient, lower gas pressure is used to minimize fluid friction and resistance. At low speeds where these effects are insufficient, higher gas pressure is applied to ensure reliable gas layer formation, preventing bearing contact while optimizing the balance between friction reduction and electric efficiency.
2Loss of energy
If a gas-lubricated bearing is applied in low-speed motor operation, then friction is reduced, but the wedge and restriction effects are insufficient to form a reliable gas layer, leading to potential contact between the bearing and rotary shaft
Solution Approach 1:
The patent dynamically adjusts the gas pressure parameter based on the motor's rotation speed. In the low-speed range where the wedge and restriction effects are insufficient, the gas pressure is increased to ensure reliable gas layer formation and prevent bearing contact. As the rotation speed increases into the high-speed range where these effects become sufficient, the gas pressure is reduced or the pump is stopped, allowing the wedge and restriction effects to maintain the gas layer while minimizing energy consumption.
3Reliability
If a pump is actuated to apply static pressure to form a gas layer in low-speed range, then reliable gas layer formation is achieved, but electricity consumption by the pump increases, worsening electric efficiency
Solution Approach 1:
The patent implements a dynamic control strategy where the pump's operation is adjusted based on the motor's rotation speed. In the low-speed range, the pump is actuated to apply static pressure for reliable gas layer formation. In the high-speed range, the pump is stopped or its driving force is reduced since the wedge and restriction effects naturally maintain the gas layer. This dynamic adjustment optimizes the balance between gas layer reliability and electric efficiency across different operating conditions.
4Use of energy by moving object
If the pump driving force is reduced in high-speed range, then electric efficiency is improved, but the gas layer may become insufficient under large radial load, leading to bearing contact
Solution Approach 1:
The patent incorporates feedback control by monitoring the motor's rotation speed and radial load conditions to adjust the pump's driving force accordingly. Under high-speed conditions with small radial loads, the pump driving force is reduced or the pump is stopped to maximize electric efficiency, as the wedge and restriction effects are sufficient. However, when large radial loads are detected (such as during travel on rough roads or when steering angle is large), the pump driving force is increased to maintain adequate gas layer pressure and prevent bearing contact, ensuring reliable bearing support.
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
The system enhances electric efficiency by reducing friction and preventing bearing contact, ensuring reliable operation across varying speeds and loads through precise pump control.
Implementation Method 1
a slide bearing that is arranged in parallel with the rolling bearing on an axis of the rotary shaft to support the rotary shaft, the slide bearing being operable as a gas-lubricated bearing that achieves gaseous lubrication with gas supplied to the slide bearing
Implementation Method 2
a so-called wedge effect and a so-called restriction effect are preferably used to form this gas layer
Implementation Method 3
a so-called wedge effect and a so-called restriction effect are preferably used to form this gas layer
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
[Problem] To precisely execute control for a pump on the basis of a radial load applied to a rotary shaft of a motor in a motor bearing system that has a bearing operable as a gas-lubricated bearing by the pump. [Solution] A motor bearing system 100 has: a slide bearing 3 operable as a gas-lubricated bearing by gas supplied from a pump 30; a rolling bearing 4; and a controller 50. The controller controls the pump such that, when the motor rotation speed is equal to or higher than the first speed and is lower than the second speed, the slide bearing functions as a bearing that supports the rotary shaft and the slide bearing is operated as the gas-lubricated bearing, and when the motor rotation speed is equal to or higher than the second speed, the pump is stopped. In addition, even in the case where the motor rotation speed is equal to or higher than the second speed, the controller does not stop the pump when a radial load applied to the rotary shaft of the motor is equal to or larger than a predetermined value.