Screw Compressor Oil Feed Valve Adjusting Lubrication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing screw compressor systems face challenges in adjusting oil feeding amounts to bearings based on differential pressure conditions, leading to inadequate lubrication at low pressures and excessive oil discharge at high pressures, which affects performance and reliability.
Innovation Solution
Incorporating an oil feeding amount adjusting unit with a valve element that reciprocates within a cylinder, featuring multiple flow paths of different areas, and a solenoid valve to control oil flow according to differential pressure, allowing for dynamic adjustment of oil feeding to bearings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the oil restrictor size is increased to ensure sufficient oil feeding at minimum differential pressure, then bearing lubrication reliability is improved, but oil feeding amount becomes excessive at higher differential pressures causing suction gas heating and performance reduction
Solution Approach 1:
The patent applies a dynamic adjustment mechanism where the oil restrictor opening degree is automatically varied based on differential pressure conditions. The adjusting unit includes a valve element that reciprocates within a cylinder, switching between multiple flow paths with different flow areas according to differential pressure, enabling the system to adapt oil feeding amount to actual operating conditions rather than using a fixed restrictor size
Solution Approach 2:
The patent changes the parameter of oil restrictor opening degree dynamically based on differential pressure. By switching between different flow paths with different flow areas, the system adjusts the oil flow restriction parameter to match operating conditions, ensuring sufficient lubrication at low differential pressure while preventing excessive oil discharge at high differential pressure
2Productivity
If the oil restrictor restriction amount is increased to reduce oil feeding amount and improve compressor performance, then suction gas heating is reduced, but bearing lubrication becomes insufficient at minimum differential pressure causing reliability reduction
Solution Approach 1:
The system dynamically adjusts the oil restrictor opening degree based on real-time differential pressure conditions. At minimum differential pressure, the valve element positions to provide a larger opening degree for sufficient lubrication, while at higher differential pressures, it reduces the opening degree to prevent excessive oil discharge, thus maintaining both reliability and performance across varying operating conditions
Solution Approach 2:
The patent dynamically changes the oil restrictor opening degree parameter in response to differential pressure variations. The adjusting unit switches between multiple flow paths with different flow areas, effectively modulating the restriction parameter to ensure optimal oil feeding amount for each operating condition, preventing both lubrication deficiency and excessive oil discharge
3Device complexity
If a fixed size oil restrictor is used to simplify the structure, then device complexity is reduced, but the system cannot adapt to varying differential pressure conditions leading to either excessive or insufficient oil feeding
Solution Approach 1:
The patent introduces a dynamic adjustment mechanism with a valve element that reciprocates within a cylinder based on differential pressure conditions. This dynamic structure switches between multiple flow paths with different flow areas, enabling the system to adapt oil feeding amount to varying operating conditions while maintaining a relatively compact and integrated design
Solution Approach 2:
The oil feeding amount adjusting unit operates automatically based on differential pressure conditions without requiring external control. The valve element self-adjusts its position according to the pressure differential, selecting the appropriate flow path to provide the correct oil feeding amount for current operating conditions, thereby achieving adaptability through self-regulation
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 ensures a sufficient oil feeding amount to bearings even at low differential pressures while preventing excessive oil discharge at high pressures, enhancing compressor performance and reliability by optimizing lubrication and cooling.
Implementation Method 1
an oil feeding passage formed in the casing for feeding oil on a high pressure side to the bearings by a differential pressure between the high pressure side and a low pressure side
Implementation Method 2
the plural flow paths are switched to adjust an oil feeding amount to be fed to the bearings by moving the valve element in accordance with the differential pressure
Implementation Method 3
a solenoid valve opening/closing the suction-side communicating path
Implementation Method 4
Each of the rolling bearing and the ball bearing has a rolling surface or a sliding surface. It is necessary to form thin oil films on these surfaces to prevent direct contact between metals
Implementation Method 5
a force fed lubrication system in which respective bearings are lubricated by forcibly feeding lubricating oil into the bearings and generated frictional heat is discharged to the outside through the forcibly fed lubricating oil
Data Source
AI summary
A screw compressor includes a screw rotor, an electric motor for driving the screw rotor, bearings supporting the screw rotor and casings housing these members. The screw compressor also includes an oil feeding passage formed in the casing for feeding oil on a high pressure side to the bearings by a differential pressure between the high pressure side and a low pressure side and an oil feeding amount adjusting unit placed in a middle of the oil feeding passage, the oil feeding amount adjusting unit includes a cylinder, a valve element provided to reciprocate inside the cylinder, and plural flow paths provided in the valve element having different flow path areas, the plural flow paths are switched to adjust an oil feeding amount to be fed to the bearings by moving the valve element in accordance with the differential pressure between the high pressure side and the low pressure side.