마찰재 그루브에 따른 습식 클러치 드래그 토크 변화 연구
Effect of Angle and Density of Grooves between Friction Plate Segments on Drag Torque in Wet Clutch of Automatic Transmission
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초록
As the importance of transmission efficiency to reducing fuel consumption and conserving the environmentrapidly increases, reducing the drag torque in an automotive wet clutch is emerging as an important issuein the automotive industry. The drag torque in a clutch occurs from viscous drag generated by automatic transmissionfluid in the narrow gap between separate friction plates. In this study, the drag torques in an automotivewet clutch are investigated with respect to the angle and density of the grooves between separate friction platesby three-dimensional finite element simulation of a single set of wet clutch disks considering the two-phase flowof air and oil. The simulation results shows that the drag torque generally increases with the rotational speed toa critical point and then decreases at the high-speed regime. The grooves between the plates plays an importantrole in reducing the drag peak, and the inclined angle of the grooves affects the oil flow. The grooves with anangle of 50° shows the lowest drag torques at both low and high speeds. The flow vectors inside the 50° groovesshows clear evidence that the fluid flows out more easily from the grooves compared with the flow vectors insidegrooves with lower angles. The simulation results shows that increasing the number of grooves (density ofgrooves) decreases the drag torque.
Abstract
As the importance of transmission efficiency to reducing fuel consumption and conserving the environmentrapidly increases, reducing the drag torque in an automotive wet clutch is emerging as an important issuein the automotive industry. The drag torque in a clutch occurs from viscous drag generated by automatic transmissionfluid in the narrow gap between separate friction plates. In this study, the drag torques in an automotivewet clutch are investigated with respect to the angle and density of the grooves between separate friction platesby three-dimensional finite element simulation of a single set of wet clutch disks considering the two-phase flowof air and oil. The simulation results shows that the drag torque generally increases with the rotational speed toa critical point and then decreases at the high-speed regime. The grooves between the plates plays an importantrole in reducing the drag peak, and the inclined angle of the grooves affects the oil flow. The grooves with anangle of 50° shows the lowest drag torques at both low and high speeds. The flow vectors inside the 50° groovesshows clear evidence that the fluid flows out more easily from the grooves compared with the flow vectors insidegrooves with lower angles. The simulation results shows that increasing the number of grooves (density ofgrooves) decreases the drag torque.
참고문헌 (10)
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