A Fundamental Study on Dynamic Contact Behavior of an Ultrasonic Motor (Coexistence of Stick and Slip Contact Zone)

2012 ◽  
Author(s):  
Takafumi Ohnishi ◽  
Tomoaki Nakayama ◽  
Kiyotaka Yamashita ◽  
Kohro Takatsuka ◽  
Tsuneo Akuto ◽  
...  
Keyword(s):  
Contact Zone ◽  
Numerical Technique ◽  
Dynamic Contact ◽  
Ultrasonic Motor ◽  
The Finite Element Method ◽  
Fundamental Study ◽  
Contact Behavior ◽  
Static Contact ◽  
Driving Torque ◽  
Contact Mechanism

We discuss the dynamic complex contact behavior between the stator and the liner that sticks to the rotor of an ultrasonic motor. An ultrasonic motor is powered by the vibration of the stator and operated by a frictional force between them. Therefore, it is important to examine the dynamic mechanism of the contact behavior to improve the energy efficiency and durability of the ultrasonic motor. We already proposed a numerical technique using the finite element method (FEM) on the basis of incremental theory to analyze the behavior of the complex contact zone which contains non-contact zone, slip contact zone and stick contact zone in a non-rotating rotor as a static contact problem. In this paper, we expand this numerical technique from a non-rotating rotor to a rotating rotor and propose a numerical technique to analyze the dynamic behavior of this complex contact zone. Moreover, we clear the dynamic contact mechanism and the driving characteristics of the ultrasonic motor such as the dependency of driving torque on the maximum frictional co-efficient.

Fundamental Study on Contact Behavior of Ultrasonic Motor

2005 ◽  
Author(s):  
Daichi Nakajima ◽  
Tomoyuki Ozawa ◽  
Takeshi Maeda ◽  
Michio Tsukui ◽  
Kohro Takatsuka ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Energy Efficiency ◽  
Finite Element ◽  
Frictional Force ◽  
Numerical Technique ◽  
Ultrasonic Motor ◽  
The Finite Element Method ◽  
Fundamental Study ◽  
Contact Behavior ◽  
Lining Material

We discuss the contact behavior between the stator and the lining material that sticks to the rotor of an ultrasonic motor. The ultrasonic motor is powered by the vibration of the stator and operates with a frictional force between the stator and the lining material. Therefore, it is important to examine the mechanism of the contact behavior to improve the energy efficiency and durability of the ultrasonic motor. We propose a numerical technique using the finite element method to examine the contact behavior between the stator and the lining material. Then, we compare the numerical example with the theoretical solution proposed by L. A. Galin and confirm the validity of our technique. Moreover, on the basis of incremental theory, we use our technique to numerically examine the complex contact behavior of the non-contact zone, slip zone and stick zone in a non-rotating rotor.

scholarly journals 809 A Fundamental Study of a Dynamic Contact Mechanism of an Ultrasonic Motor

2009 ◽  
Vol 2009.46 (0) ◽  
pp. 305-306
Author(s):  
Kiyotaka YAMASHITA ◽  
Kohro TAKATSUKA ◽  
Daichi NAKAJIMA ◽  
Tomoyuki OZAWA ◽  
Tsuneo AKUTO
Keyword(s):  
Dynamic Contact ◽  
Ultrasonic Motor ◽  
Fundamental Study ◽  
Contact Mechanism

605 A Fundamental Study of Contact Behavior of an Ultrasonic Motor

2004 ◽  
Vol 2004 (0) ◽  
pp. _605-1_-_605-6_
Author(s):  
Daichi NAKAJIMA ◽  
Tomoyuki OZAWA ◽  
Kohro TAKATSUKA ◽  
Takeshi MAEDA ◽  
Michio TSUKUI ◽  
...  
Keyword(s):  
Ultrasonic Motor ◽  
Fundamental Study ◽  
Contact Behavior

scholarly journals A Fundamental Study of Contact Behavior of an Ultrasonic Motor

2006 ◽  
Vol 72 (717) ◽  
pp. 1590-1597
Author(s):  
Daichi NAKAJIMA ◽  
Takeshi MAEDA ◽  
Tomoyuki OZAWA ◽  
Michio TSUKUI ◽  
Kohro TAKATSUKA ◽  
...  
Keyword(s):  
Ultrasonic Motor ◽  
Fundamental Study ◽  
Contact Behavior

The Pressure Drop and Dynamic Contact Angle of Motion of Triple-Lines in Hydrophobic Microchannels

2010 ◽  
Author(s):  
Dongin Yu ◽  
Chiwoong Choi ◽  
Moohwan Kim
Keyword(s):  
Contact Angle ◽  
Pressure Drop ◽  
Liquid Film ◽  
Dynamic Contact Angle ◽  
Triple Line ◽  
Dynamic Contact ◽  
Superficial Velocity ◽  
Channel Diameter ◽  
Fluid Property ◽  
Static Contact

At two-phase flow in microchannels, slug flow regime is different for wettability of surface. A slug in a hydrophilic microchannel has liquid film. However, a slug in a hydrophobic microchannel has no liquid film instead, the slug has triple-lines and makes higher pressure drop due to the motion of the triple-line. In previous researches, pressure drop of triple-line is depended of dynamic contact angle, channel diameter and fluid property. And, dynamic contact angle is depended of static contact angle, superficial velocity and fluid property. In order to understand the pressure drop of motion of triple-lines, pressure drop of slug with triple-lines in case of various diameters (0.546, 0.763, 1.018, 1.555, 2.075 mm), various fluids (D.I.water, D.I.water-1, 5, 10% ethanol mixture) and various superficial velocity (j = 0.01∼0.4 m/s) was measured. Dynamic contact angle was calculated from relation of the pressure drop of slug with triple-lines. Comparing with previous dynamic contact angle correlations, previous correlation underestimated dynamic contact angle in the region of this study. (10−4≤Ca≤10−3, 10−2≤We≤10−1, 68°≤θS≤110°)

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