Research and Analysis on Hydraulic System of a Two-Stage Variable Compression Ratio Engine

2023-01-0228

04/11/2023

Event
WCX SAE World Congress Experience
Authors Abstract
Content
This study introduces the working principle of the two-stage variable compression ratio system, the layout and method of the VCR hydraulic system test. Based on the research and analysis of VCR hydraulic system test, the results shows the average pressure, degree of pressure fluctuation of the VCR conrod supply oil and the temperature of conrod journal are all strongly and positively related to engine speed. The maximum oil pressure fluctuation amplitude at VCR conrod bearing appears at 5500r/min. The temperature at VCR conrod bearing is mainly dominated by the friction between bearing and crankshaft, and its maximum value appears at 6000r/min; Meanwhile, the main contribution of engine load to the temperature is to increase temperature of the whole circle of conrod journal, and also reducing temperature difference of the whole circle. In addition, the state change of VCR hydraulic system under different conditions can reflect the state of engine compression ratio. The results of overall test show that oil pressure fluctuation of the VCR hydraulic system is in normal range, the system has good function and can meet the oil demand of each sub-component under steady and dynamic conditions.
Meta TagsDetails
DOI
https://doi.org/10.4271/2023-01-0228
Pages
10
Citation
Luo, H., Zhan, W., and Wu, G., "Research and Analysis on Hydraulic System of a Two-Stage Variable Compression Ratio Engine," SAE Technical Paper 2023-01-0228, 2023, https://doi.org/10.4271/2023-01-0228.
Additional Details
Publisher
Published
Apr 11, 2023
Product Code
2023-01-0228
Content Type
Technical Paper
Language
English