A Study on High Rotational Speed Traction Drive
-Measurement and Improvement of Traction Coefficient Up to 50,000 rpm-

Yuechen Jia･Takeshi Yamamoto･Itsuki Maehira･So Kokubo (Tokai University)

A high-speed traction drive test machine was manufactured, and performance up to 50,000 rpm was measured. And a model was constructed to accurately predict the traction coefficient, and a texture was created that significantly improved performance. The effects of increasing the reduction ratio were also experimentally confirmed.

Study of the Cooling Effect on the Roller Surface by Increasing the Oil Feed Rate in a High Peripheral Speed Traction Drive and its Cooling Modeling by Thermo-Fluid Analysis

Shunki Boku･Yuki Kawamoto･Katsuyoshi Sato･Masayuki Ochiai (Tokai University)

In recent years, the traction drive has been identified as a potential power transmission mechanism for electric vehicles. However, one issue with traction drives is that the traction coefficient decreases as the roller surface temperature rises, which may impair the transmission capacity. It is important to address this concern.
This study conducted temperature measurement experiments for different oil supply rates and found that an increase in oil quantity does not contribute to cooling effectiveness.
Furthermore, a thermal fluid analysis model was tried to calculate the roller surface temperature.

Development of Magnetostrictive Torque Sensor System
-Development of Compact Torque Sensor System Capable of Mounting in Vehicle Powertrain-

Kimiko Nakai･Kota Fukuda･Satoshi Oyama (NSK)

This paper reports on the magnetostrictive torque sensor system mountable in the powertrain. With a compact and robust structure for powertrain applications, the developed torque sensor system offers superior mountability. The sensor demonstrated accurate torque measurements for ±1 000 Nm of torque input on a shaft with an outer diameter of 40 mm within a 4% error.

Development of Insulation Bearing in Motor Support Bearing Application (First Report)

Voelkel Franz･Brehm Daniel･Kuhn Lukas (Schaeffler Technologies)･Seiya Nishizawa (Schaeffler Japan)

BEVs with high voltage inverters are getting bigger market share in the future.
With this trend, the risk of the damage on the motor bearings rooted from parasitic current going through the inside of the motor units are getting more critical. with that problem, the simulation approach and test methods are developed and practical and cost-effective solution of insulation bearing are proposed.

Elucidating the Mechanism of Hydraulic Noise using CFD

Masaru Shimada (JATCO Engineering)

Hydraulic system noise was often solved by trial and error in experiments. To solve it, CFD that reproduce the regulating pressure behavior of valves was conducted and analyzed the flow field in detail. The results revealed the mechanism, air in the oil expands and compresses in the circuit to generate noise, which is difficult to elucidate experimentally. In this report, the details of mechanism and countermeasures will be presented.